My girlfriend and her daughter Lynn have been living with me for over 5 years. Lynn is 22 years old now and for more than a year has began exposing herself to me. I see her naked several times a week but only when her mom is out or still a work. She has always been a little strange and very forward and many times over the years has also seen me naked through no fault of my own. I have even seen her masturbating a few times but for the last year has gotten more frequent. On the weekends when her mother is showing houses Lynn goes around with very little on seldom wearing a bra or panties. She wears these loose fitting night shirts which are not only sheer but also short and she only has to lean over slightly and I am treated to the sight of her rear and vagina. Enough that I know she shaves her pubic hair. I've told her once or twice that she didn't have enough on but all she does is grin and call me a fuddy-duddy. So I never say anything about it since then. The bad thing is I end up jerking off a lot because of it. She has a boyfriend who is a nice guy and I think he is crazy about her. If he is here she is always dressed ok but when I am alone with her she insists on giving me a show. I have to admit I enjoy seeing her like that but sometimes feel guilty I don't tell her mother about it.