I'm Chris and I'm an eighteen-year-old, awkward teenager. Blonde hair, blue eyes, average build and a seven-inch cock. I started to get a feel for wearing my sister's clothes when the house was empty one time. My sister, Annie, is twenty-one and she's stunning. All my friends want to fuck her and, to be honest, so did I. She has short blonde hair, blue eyes, 34D tits and a nice curvy ass. 

Like I said, I'd be sneaking into my sister's room when the house was empty and trying on her clothes. At first it was just bra and panties. I'd get so hard just doing that so I kept going back. Then it escalated and I started wearing full outfits when I had the time. 

I came home from work early one afternoon and everyone was out. There was a note on the kitchen worktop from my parents telling me they'd gone to visit relatives for a few days so it would be just me and my sister for the weekend. My sister was in work that day. She worked in a bar so I thought she would be late home ; I decided to use this opportunity to have some fun. I went up to her room, which was messy as usual, and searched for my favourite bra and panty set—a pink, lace thong which wouldn't keep my cock in if I tried and a matching bra that was very low cut. I'd stuff the bra with my socks to make sure it seemed full.

As soon as I felt the lace on my cock I was instantly hard so I lay on my sister's bed feeling my "boobs" and rubbing the tip of my cock, pretending it was my clit. I closed my eyes and imagined that it was my sister's tongue doing the work. I just kept working myself to the edge and then I'd stop and calm down before rubbing again. I kept edging for about twenty minutes and, in my pleasure, didn't notice that Annie had come home early.

Suddenly I heard a scream, opened my eyes and saw Annie stood there in the door way.

"What the fuck are you doing, you creep? You're wearing my underwear; get them off now!" she yelled.

"Please don't tell Mum or Dad," I begged pathetically, "You know they'll kill me. I'll do anything."

"Get out of my room now and don't even think about coming back, you pervert. I can't believe I'm stuck with you all weekend," moaned Annie.

I quickly got dressed and left the house, tears down my face. I'd fucked up badly and I knew if she told Mum or Dad I was doomed. I wandered aimlessly round the local park for a couple of hours before walking back home. I went to my room and found the bra and panty set on my bed with a note which read:

You said you'd do anything. Put these on and come knock on my door. I'll see you soon, Christina x

What was my sister planning? This was wrong but also a dream come true.

I was hard just reading the note so I quickly stripped and put the underwear on. I stood outside her door and hesitated before I knocked. What was she going to have me do. She had already given me a girl's name. I swallowed and knocked. I had to stop her telling my parents at least.

The door opened and my sister pulled me into her room. Annie shoved me onto her bed and then pinned me down.

"Right then, little sister," she laughed, "I want to see how much of a girl you really are. If you do as I say, nobody has to know about this."

"I'll do anything, honest," I replied nervously.

"Well, if you really want to be a girl," she said, "You need to swallow some cum. But you can't have all the fun."

Annie pulled her jeans and panties off and then sat on my face and told me to start licking her clit whilst she pulled my cock out of the thong. Her pussy was dripping on my face and it smelt fantastic. It really was a dream come true. I stuck my tongue out slowly and started to trace her lips. I felt her take my cock into her mouth. She wasn't being nearly as gentle as me and start to suck hard. She wanted me to cum fast. I could feel her tongue swirling round my head as she fucked me with her mouth. In response, I shoved my tongue deep inside her and started to rub her clit with my fingers. 

As I got more aggresive with her she started to drip more and more pussy juice on my face. Suddenly, she stopped sucking my cock and I was confused. Had I done something wrong? Then I noticed she was licking one of her fingers which she then start to push into my ass.

"No! What are you doing?" I yelled.

"A real girl gets fingered, Christina; take it like a real girl," Annie cackled as she took my cock back into her mouth.

I gritted my teeth and tried to concentrate on eating her pussy. It felt strangely good having her finger in my ass and deep-throating my cock. I was getting close and she knew it. Annie started to pick up the pace, fingering faster and sucking harder. I gasped into her pussy and started to twitch as I came ropes into her mouth. She slid her finger out of my ass and sat up. Then she kissed me passionately, transfering the cum into my mouth. I couldn't stop her doing it and just held it there in my mouth. Finally she stopped kissing me.

"Well, little sis, it's time to swallow like a real girl," she ordered.

I nodded and gulped the cum back. What had I let myself in for? My sister could do what she wanted to me for the whole weekend.

"Good girl," she said. "That's enough for tonight. Go to bed. Keep the panties on; I'll be using you more tomorrow."