LOL, same here.. her ass was just a not go area for me. She didn’t liked it, it hurts and so.
When she invited a guy she really liked, at our home ( guy didn’t knew i was also in the house watching with hidden cam) he was fucking her hard and I enjoyed watching. Suddenly I heard him say something about her ass and I thought ‘ bad luck hombre, she doesn’t want it’.
But to my surprise she immediately put her ass to him and he stuck his big cock in her. That was shocking for me haha but on the other hand such a turn on. She let him do what was forbidden for me.
When he left and I went to our bed I asked her about it. She said: I like him so much and he can do whatever he wants with me, even dough it hurt a bit, it felt so good to be his slut.
Man, that made me so horny. Knowing that 5 minutes ago she gave herself totally to another guy to please him.