Hard to Explain - Sister in Law Drives me Wild

My sister in law came to live with us for a few months to help us out. We are extremely busy and the extra pair of hands was simply the best thing that had happened to us in a long time. For me though, having her live with us brought an extra complication, controlling myself around her. You see, she is everything I could have possibly have fantasized about in a woman. Big tits, big sex drive, open and willing to try new things. She is beautiful as well, which obviously helps, or doesn't depending on your viewpoint.

We have grown closer over the years, but it was the last time she visited that I really started to look at her differently. Now that she is here for an extended period of time, I find my gaze lingering, and on a few separate occasions I have found myself going thrrough her dirty laundry and cumming while smelling her panties or wrapping them around my hard cock.

She appears unaware of my desires though I am sure that I don't hide it that well. She is often in low cut shirts or a bikini, showing off her DD's and tanned, sexy body. I have thought so many times about just letting her know how sexy I think she is, but I just don't want to complicate things. I have on a few separate occasions taken her dirty panties out of the laundry, and shot my load into them, though I was careful to put them in the washer so she wouldn't notice.

Knowing the implications of a relationship with her, my thoughts have turned to trying to seduce her into a mutual masturbation session :) I know that while she is staying wtih me she isn't exactly going out and meeting men, and my current situation is dire when it comes to sex. I havent decided whether to just let her catch me in the act or to verbally approach her with the idea. I am hoping to see any sign whether she is interested at all. I will let you know how it goes!