I'm a male 50 and my sister is 40, I had not seen her in 3 years and at xmas time we finally saw each other at our parents house. I could not believe what a sexy woman she had turned into. She had always been such a tomboy as a girl but, now she was beautiful and her ass was amazing. Since our parents now lived in a two bedroom condo I told my sister to take the bedroom and that I'd take the couch. Mom chimed in and said, "You two always liked to share a bed as teens I'm sure it'll be alright for the two nights your staying." I laughed and said, "That's because sis watched too many horror movies and was afraid of the dark." Then my sister said, "Dont laugh, Im still scared of horror movies. We all laughed and soon got ready for bed, my sister had a shower before I did and she was sitting in bed eating a piece of pie, watching tv when I came in. I just had on my boxers and I got in bed. She got up to take out her plate and as she bent over to get out of bed, her short tee shirt lifted a little and I saw her bare ass and got a glimpse of her glistening v*****, she wasn't wearing anything under that tee! I watched her walk out of the room and noticed how nice her legs were, and I was instantly hard! When she came back in I noticed that her nips looked hard under the tee shirt and I could tell she was looking at the bulge in my shorts. When she got into bed I wanted to grab her but, instead I said, "These boxer shorts are driving me nuts, I'm not used to them because I usually sleep in the nude." She laughed and said, "Take them off, I'm not wearing anything under this shirt cause I usually sleep naked too. I said, "Ok," and I slid them off, She looked at my hard-on and said, "Wow,,,," then she pulled her T-shirt off and needless to say we f***** all night long and twice the next morning and I have to say it was the best s** I ever had!!! I guess it goes without saying that we've made plans to get together again real soon!