I once went for a massage in Phoenix AZ with a VERY hot guy. After 15 minutes of massage things escalated to full passionate sex, and he fucked me. It was really hot! When I finished, to my surprise he asked me to fist him. He was a very good top and for some reason I wasn't expecting that, and it was also something I had never done before, but I thought... why not? Also, he really turned the massage into something quite unexpected and really great for me, he was a nice guy and I felt like reciprocating the pleasure he gave me.
No, I didn't enjoy it at all, and I have to say that I am not good at all at that!