I'm thirty-three and have a hot nineteen-year-old sister-in-law. I've made it a ritual to take my sister-in-law shopping for my wife's birthday gift every year. I love making her try on the skimpiest of outfits and ogle at her. She's aware of this and enjoys the attention. This year, I took her to a store and made her try a few skimpy outfits. I was really turned on, so I decided to pass on some sexy transparent lingerie to her and asked her to try it on. Being the tease that she is, she agreed to wear it to see how it looked, but said she wouldn’t let me see her in it. I was too eager just to get her into it, so I agreed. I waited for a few seconds, and then pulled open the curtain to the trying room slightly and poked my head in. She had got the panties on and was just fastening the bra. I got a brief glimpse of her breasts before she put it on. She saw me looking at her and gave a naughty smile as if she was expecting me. "So what do you think?" she said, as she twirled around to show me the outfit from all sides. She looked heavenly in the see-through lingerie and I could see every detail of her young body in it. I was too awestruck to even reply. Finally, I placed my hand on her breast and said it looks wonderful on you. She pushed my hand away and said, "You'll have to buy it for me for doing this." I bought her that pair of lingerie and have been buying her gifts ever since in exchange of little favors like feeling her up and seeing her breasts. She doesn’t let me go any further than that, but I’m still a happy man.