My wife's twin sister loves nothing better than teasing me. A glimpse of a tit with her shirt unbottoned or spreading her legs and showing her panties. I know she knows what she is doing because each flash is usually followed by a sly grin. But it is always done in the presence of her husband or my wife without them knowing what she is doing. If by chance it is just me and her together she plays the role of the proper sister-in-law.
So, I figured out a way to get even with her. They live next door to us and I have a key to their house. I have started getting her soiled panties and jacking off while I lick and suck the crotch. The odour of her pussy drives me wild. When I get ready to cum I go to her dresser drawer and take out a pair of her clean panties and dump my load in the crotch of the clean pair.
I fold them neatly and put them back in the drawer. She just flashed her panties at me a few minutes ago and I noticed she has on her white panties. Those are the ones I came in yesterday so I hope my dried cum is getting all over her pussy.
I would give anything to fuck her good but I guess I will just have to keep jacking off to the smell of her juicy pussy.