"Please, just once so I know what it's like."
"Okay, but if things get out of hand, we'll have a problem."
"I can deal with Woody. Besides, he's afraid of you."
Tia had said she wanted "to be watched" before, and now she was really up for it. So, fine, I thought, we can kill two birds with one stone. I was sharing an apartment with a guy named Woody (I kid you not). Woody was, to put it most kindly, flat fucking ugly. He would do just about anything to get laid, or just see a pair of bare breasts. Tia's exhibitionist streak would give him a bit of fun.
I went to the local mall with Tia and we picked out a few items that were either ready to go or easily modified to fit the bill. A bit of preparation and we just had to wait for Woody to go to bed. About 10 PM he called it a night and I gave Tia the sign. She slipped into our room and came back in her outfit for the evening.
She was wearing a pair of bikini panties, bright pink, and a T-shirt that had been cut off to expose the underside of her DDs, tight enough that her nipples stood out clearly.
"Are you sure he's asleep?" This loud enough to wake him if he was, but I was betting he was doing his nightly wank and not yet asleep. Her voice was, I figured, enough to get his attention and sure enough, the door to his room opened quietly just a hair.
"I don't care if he's asleep or not, I want you."  I hoped that would be enough clue for Woody to know it was okay to do some Peeping Tom.
Tia walked over to where I was sitting and knelt in front of my chair. Her breasts escaped from the t-shirt. She leaned forward and pulled my shorts down and started giving me head.
"Don't forget your pussy" I ordered.
Her hand slid across her belly and slipped into her panties. From his viewpoint Woody could see her moving around under the material of her bikini.
I let her suck me for a few minutes until I heard the moan that indicated she was getting to the explosive stage.
"Okay, stand up."
She pulled off of my shaft reluctantly, and stood with her hand still in her panties. She made sure to face Woody's door so he could see her barely covered breasts and what she was doing to herself.

I heard a low moan from that direction. Good.
I turned her around and lead her to the window. It looked out over the street one storey below and the foot traffic was consistent given the number of bars in the area. I pulled her top off and slid her panties down and off. I turned her to face the window and ran my hands over her body for a while, nibbling on her shoulder and prodding her ass with my erection. She was working her left breast and her pussy when I wasn't paying attention to those spots. I glance out the window and saw a couple of guys standing slack-jawed across the street. I recognized one from our favorite watering hole. He'd been in our apartment a few times for "after hours" and I knew he recognized Tia and could probably figure out who those extra hands belonged to.
"There Frank" I whispered. Tia giggled. She'd have some fun with him next time we went to the bar.
I pulled her away from the window and over to a table where we played poker some night. Today the "poker" table would live up to its name. I laid her out on the table and put her ankles on my shoulders. I slid into her and started pumping. I peeked to side and saw Woody, naked from the waist down in his doorway and pumping frantically at his cock. I tried to coordinate everybody, but Woody came first, shooting out onto the carpet. Tia gave one of her best performances, screaming and bucking on my cock as she and I finished together. I kept her on the table a bit longer, "cleaning up" as she liked to put it and giving her another orgasm.
When I was done, and she was too, I glance around to see Woody's door was closed.
"Was it what you'd hoped?"
"Oh, yes, I peeked at Woody and having  him jerk off while watching us fuck was just what I'd hoped for. Frank was a bonus. I can't wait to see him at the bar. He'll probably run for the bathroom when he sees us next."
"Glad you liked it, sweetie."
"Very much. Now, about that other fantasy..."
"We'll see, we'll see. Gotta find somebody to drive the car, and find a car with a roof rack so we don't slide off."