Curvy sis challenges me not to get hard
I have a thicc stepsister who is around my age. When we are home alone we like having fun and she comes up with very creative ideas… we were sitting on the sofa one day and I was looking at her big boobs when she noticed I was paying too much attention to them. She explained we could do something for entertainment, a "challenge". When I asked what the challenge was she said we would both get completely naked and if I got a boner I would lose. I couldn't believe what was happening but we both got naked and I got a big erection. She told me she was very turned on from it and let me touch her pussy to feel how wet she was. We couldn't resist fucking and now I want to bang my sis everyday.