Helen knew from the loud, passionate noises behind the bathroom door that her father - as she had planned with Caro - was fucking her best friend. The thought of watching her father screw Caro made Helen wet with anticipation; she'd never seen anyone fucking before, so her excitement must simply be that.

Now was her chance, she thought. She grinned, opened the squeaky door, and walked into the bathroom. Her father briefly turned his head towards her, then his lust-filled face turned back to Caro, and he continued ramming his massive fat cock into her best friend hard from behind.

She had promised Caro a photo, so she took out her phone, watched her father pound Caro's pink, teenage pussy, and waited for the right moment.

Caro was moaning loudly, in time with the thrusts. Then Caro squealed and visibly shivered as Helen's father groaned and thrust his hips forward, his butt cheeks clenching as he unloaded into her best friend.

When Helen clicked the shutter, the flash went off, and her father turned briefly towards her again. She was surprised when he continued to slowly shaft Caro, his huge glistening cock emerging briefly from Caro's wet pussy before being driven into Caro.

"A souvenir," she said.

After a bit of banter later, her father finally pulled out, his enormous glistening pole waving, still rigid, in front of him. He's got a massive dick, Helen thought. I wonder what it's like to be fucked by a monster like that. She blushed when she realised she was wet at the thought of her father's enormous member inside her.

Her father fucked Caro repeatedly for the rest of the weekend, and Helen discovered she was jealous. It just won’t do, she thought. I am not going to fuck my father.

She decided to find a surrogate; she needed to be fucked by a different cock, so Helen vowed to find an equally impressive one when she returned to university and banish her father's monstrous dick to harmless memory.

Finally, it was Sunday evening, and the weekend was over; a taxi deposited Helen and Caro at the station. They boarded their train and eventually found a table in the last carriage of the crowded train and sat opposite each other against the windows.

Helen took out her phone and sent Caro her souvenir photo.

"You obviously enjoyed yourself, Caro," Helen said.

When her phone pinged, Caro opened it and grinned. She leaned forward.

"Yes, it was marvellous," she whispered. "Your dad is fantastic; he made me come so many times, I lost count; I love his gigantic fat tool, and I swallowed gallons of his cum."

The vision of her father's glistening erection passed through her mind. Helen felt guilty and ashamed that the sight of her father fucking Caro aroused her so much, and she tried to dismiss the memory, but Caro's words brought the memory flooding back, and she found herself wondering what it would be like to be stretched by that monstrous fat cock. She felt her nipple harden and a damp patch formed in her panties.

"Yes, I heard the pair of you having fun the entire weekend," she said. "Like rabbits, I was quite envious."

Helen blushed when she realised it was true; she had repeatedly imagined that monstrous dick inside herself, fucking her hard. It really won't do. She would not commit incest, however much the thought of her father's enormous cock tempted and aroused her.

Caro grinned. "He certainly has stamina; I am so sore, I can hardly walk right now."

Helen had hardly seen the pair of them all weekend. She grinned back at her best friend.

"Little blue pills," she said. "Daddy's probably still got a boner."

Caro laughed.

---

Over the next few days, Helen tried to forget the incident, but the vision of her father's monstrous, glistening cock ramming into her best friend kept returning. Each time, she ignored it and renewed her vow to find another huge cock to fuck her instead.

Thursday rolled around before a chance presented itself when she visited her college's library to complete an assignment.

All the university colleges had one of those ancient medieval edifices, half-timbered, with ranks of ancient tomes chained to their bookcases. Unusually, hers also had a vast modern extension dedicated to the physical sciences.

Helen sat at one of the old mahogany desks in the central seating area of the deserted library, opened her laptop, and started writing the paper. But her heart wasn't into it, and she couldn't concentrate.

She covertly watched the librarian as he pottered around the library, returning books to their shelves. Though grey-haired, the man was tall and well-built, with a pert arse. He reminded her of someone, but she couldn't place who. Helen decided she rather fancied him and wanted to flirt with him. The first step would be getting him to notice her.

The library was warm, so she took off her heavy coat. Under the coat, she wore a short, strappy white dress that only reached part way down her thighs. When she sat back down, she ensured the dress rode up, exposing her thighs to view. She leaned forward over the desk so the librarian would have a good view into the low-cut top.

Sure enough, the next time the librarian walked past, she caught him staring at both her legs and cleavage. The man blushed when he realised Helen had noticed him watching. She grinned back at him and looked him up and down, her gaze lingering on his groin where his trousers bulged from his erection. Helen decided the bulge was large enough to warrant her attention.

She leaned back and stretched, pushing her big boobs forward so her hard nipples strained against her skimpy dress.

"Time for a break," she said.

She stood, clasped her hands high above her head and did a couple of sideways stretches as if she was stiff from sitting hunched over her laptop for too long.

The man ogled her and licked his lips.

"That's better," Helen said. She looked down at the man's erection and smiled broadly. "Everything was all stiff and rigid."

The librarian blushed, his gaze still fixed on her chest.

Helen thrust her chest out, reached up and tweaked her nipples through her dress.

"Do you like them?" she said.

The librarian laughed. "You're really quite a slut, aren't you?" he replied.

"Whatever you say, Daddy." Helen smiled hungrily. "Now kiss me, you idiot, before I change my mind."

The librarian put his arms around Helen and kissed her. She felt a hand slide down her back, reach under her dress, and caress her arse. The librarian's hand slid around her body, and a finger probed her moist crack. She moaned as the finger slid inside her.

Helen probed his mouth with her tongue as his invasive finger probed her pussy. A second finger joined the first in her wet minge, and the two hooked fingers were soon wet with her juices, finger-fucking her hard and fast.

The librarian pushed her away. "Show me your fabulous boobs."

Helen slipped the straps off her shoulders and allowed the top of her dress to fall to her waist, revealing her big, perfect tits. The librarian leaned down, and Helen felt his tongue circle her hard nipples, and his teeth gently nipped them as he sucked each breast in turn.

Helen reached into the librarian's trousers and felt his erect dick, then she knelt in front of him and looked up at him with wide eyes.

"Please, daddy, can I suck your cock?" Helen implored him, hoping her pussy would soon be stretched by an enormous fat cock.

The librarian looked around the deserted library nervously.

"Okay, go on then," he said finally.

Helen unbuckled his trousers and pulled them down. His massive erection strained against his underpants and sprang free, waving in front of her face when she pulled his undies down. His cock was long, almost as long as her father's but not as fat. Helen felt a flush of arousal as that persistent image of her father fucking Caro with his monstrous wet dick flashed through her mind. Helen dismissed it, focusing instead on the cock waving before her nose. It should fill me up nicely. Helen decided she'd let the man fuck her. But first things first.

She pulled back his foreskin, exposing the pink tip of his long hard dick. She held his dick with one small hand and briefly teased him, flicking her tongue across the end, then wrapped her lips around his cock and started to suck him as her hand wanked his long rigid shaft.

The librarian's rigid dick was far longer than the few she had sucked before, and the tip uncomfortably hit the back of her throat when she took him into her warm mouth, her hand still wrapped around his shaft. No one had been allowed to come in her mouth yet, and she wondered what that would be like as she sucked him. Would she be able to swallow as she knew Caro had done with her father's cum?

After a few minutes, she could stand it no more; she wanted his cock inside her. She pulled her head back; the librarian's wet cock left her mouth, waved just in front of her nose, and Helen looked up at him with wide eyes.

"I want you to fuck me now," she said.

The man scanned the library and looked briefly at the entrance. They were still alone.

"I could lose my job," the librarian said.

Helen sat down and hooked her legs over the mahogany arms of the chair, pulling the gusset of her panties aside, so her tight pussy was exposed on the edge of the seat.

"Come on, fuck me, daddy," she implored him. "You know you want to."

The librarian still hesitated, eyes fixed on her shaved pussy, and one hand wanking his long hard erection. Helen spread her pussy lips with one hand.

"Alright, I'll fuck you," he said. "Hard, the way sluts like you deserve."

The librarian came closer, pulled her panties firmly to one side, and, with one hand, rubbed the tip of his long rigid cock up and down her slit, parting her labia and teasing her. As he did so, Helen reached down and massaged her clitoris.

Finally, Helen felt his long hard cock stretch her pussy as the tip entered her shaved cunt. She watched his rigid shaft, still wet with her spit, slide easily into her tight teenage minge. The librarian wasn't as wide; it would be marvellous to be stretched further, Helen thought. She caught herself; she was fucking this good-looking bloke to forget how much the sight of her father's cock had aroused her. Not to make comparisons.

She focused on the sensations as the librarian slowly fucked her. His cock glided wetly in and out of her tight pussy, glistening now with her juices.

The librarian picked up the pace until his long hard dick rammed into her with a fast but steady rhythm. Helen closed her eyes, briefly imagining a different cock inside her before she caught herself. She opened her eyes and fixed the librarian with her lustful gaze.

The staff door unexpectedly opened, and another younger man - the assistant librarian - walked in. He saw his boss, the librarian fucking Helen and stopped to stare, his mouth wide open.

"Need any help, boss?" the assistant asked. "I'd love to fuck her brains out."

"Tell her to suck your cock," the librarian said, his earlier nervousness forgotten, as he shafted Helen's tight wet pussy.

Helen knew she was in a situation of her own choosing, but she wasn't just a fuck-toy to be used and discarded.

"Don't I get a say in this?" she objected.

The librarian laughed, rammed his cock balls-deep into her, moved his face close to hers, and kissed her.

"No, you don't. You literally threw yourself at me," the librarian said. "Now be a good little girl, do what you're told, and suck my assistant's cock."

She was angry, but with the librarian's disappointing long cock deep inside her, she wasn't in a position to argue coherently. She decided to accept the situation and play along for now. And perhaps the assistant would be better endowed with a fatter dick. She consoled herself that she quite liked sucking cock.

She looked up at the librarian's handsome face.

"Yes, daddy," she said. "I promise I'll be a good girl."

She turned her head and looked the assistant in the eyes.

"Come on, big boy," she said. "Show me what you've got."

The assistant dropped his trousers and pulled his undies down, releasing his hard, merely adequate cock. Helen was disappointed; she had hoped he would sport a gigantic fat monster.

She mentally shrugged; it might be disappointing, but she had never played with two cock before. When the assistant came close, she opened her mouth and let the man thrust his rigid, circumcised member into it.

The assistant put his hands behind her head, held her still, and started thrusting his disappointing erection into her mouth.

Helen didn't like the way the assistant was using her. He was fucking her face; that was the only way to describe it - she wasn't sucking him properly; Helen loved the feeling of power when she set the pace, knowing she controlled when they would come. She pushed the assistant angrily away and then looked up at the librarian.

"I want to suck both of you together," she said. "I've never sucked two cocks before."

The librarian just nodded and pulled his long dripping cock out of her tight teenage cunt.

Helen stood, and the two half-naked men - the librarian in just his shirt and tie and his assistant still with his trousers and undies around his ankles - came close and fondled her perfect boobs. She kissed each in turn before kneeling between them.

She grabbed a hard cock in each hand. Both men moaned as she sucked and wanked their erect cocks, alternating every few bobs of her head. The librarian's cock hit the back of her mouth each time it was his turn to be sucked, and Helen almost gagged when he tried to pull her further onto his long cock.

A few alternations later, the assistant groaned.

"Enough; I don't want to cum yet," the assistant said. He looked at his boss. "And it's my turn to fuck this bitch."

Helen rose from her knees, pulled her panties down and bent over the polished wooden rail that separated the shelves from the seating area. Her knickers had fallen to around her knees, and her white dress was bunched around her waist. The assistant slammed his rigid dick into her tight pussy and fucked her from behind.

The librarian walked around the rail and slowly thrust his long hard cock into her mouth.

"How much can you take, slut?" he asked.

He put his hands behind her head and gently pulled her onto his cock. Helen almost gagged when it hit the back of her mouth, and the pressure on her head relented. Determined not to be defeated, she sucked hard on the long rigid pole in her mouth and pushed forward to inhale more of it. This time she didn't gag, and she felt it glide slowly down her throat as the assistant slammed his erect rod into her from behind.

Helen decided she enjoyed being spit-roast like this, with one cock pounding her wet pussy as she sucked the librarian's long cock, letting him ram his hard dick repeatedly into her mouth and far down her throat. She'd be in heaven if there was a monstrous, fat cock in her tight pussy and not the assistant's barely adequate dick. Helen felt renewed jealousy for Caro.

"I want to fuck this slut again," the librarian said, with his long dick embedded down her throat and her lips pressed against his pubes.

The two men swapped places, so she was spit-roasted again. This time, the librarian rammed his long narrow cock into her wet pussy and fucked her, steadily thrusting his rigid dick balls-deep into her pussy. It was better with his long member in her pussy; she barely summoned the willpower to resist that incestuous comparison on girth.

The assistant roughly fucked her face again, his cock barely reaching the back of her mouth. Helen detested her lack of control, and she almost bit his dick in anger, but she restrained herself, her teeth stopping as they made contact with his dick. Instead, she decided she would make him come quickly, so the ordeal was over. Her lips tightly gripped his cock, and she let her tongue glide underneath his shaft with each thrust.

Sure enough, the assistant was the first of the two men to come; his short cock twitched in her mouth, filling it with a flood of hot cum, fulfilling her earlier curiosity.

Helen didn't have time to savour this new experience because, at that moment, the doors from the modern extension banged open, and five male students walked in. They stopped and stared, watching the librarian fucking her from behind as his assistant's salty cum spurted into her mouth.

Helen blushed hotly with embarrassment. She swallowed hard, but there was too much; cum oozed out of her lips, past the assistant's cock that still filled her mouth, and dribbled down her chin. The man finally noticed their audience, swore loudly, and jerked his cock out of her mouth, spraying her face with another vast wave of cum.

Almost simultaneously, the librarian pulled her hard onto his cock, and his long dick exploded deep inside her, filling her tight pussy with cum, before he - like his assistant had - panicked and withdrew mid-ejaculation, spraying her arse with cum.

Helen felt utterly humiliated, half-naked, fucked in front of five strangers and drenched in cum. Dejected, she watched the trouser-less librarian rapidly disappear through a door marked "Staff Only," his assistant following close behind him, still pulling up his trousers.

Helen knew how much of her disgrace the students had seen and that there was little chance of dignity. She pulled her knickers up from around her knees and smoothed down the skirt of her short white dress, ignoring the cum on her bum cheeks that seeped through to make a large wet patch. Then she put her arms into...