so everyone came over for cook out. SIL had on some very tight shorts and that ass was looking yummy. at some point I was walking by her and just had to grab that ass. I was not sure at first, I thought she had a thong on, but was not sure until I brushed her ass with my hand, she turned and smiled so of course I said sorry, she was like no worries. later on I was checking that ass out and she turned and smile and asked if I was looking for something. I was like well just figuring what you got on under there. she smiled and said well its Thursday..thong Thursday. so after a bit while everyone was busy she was standing by the sink and I took the chance and walk up behind her and brushed her ass with my cock which was kinda hard, she turned and smiled and said umm do it again. of course now it was much harder and I took her up and planted my hard cock right in her ass (shorts covered) and too my surprise she pushed back and wiggled that phat ass on my very hard cock. damn id like to lay the pipe to her