I've done that a lot. I'm an ass man and anytime I get to play with a hot ass, it doesn't matter if I get to fuck it or just hump it.
One time I was working my cock between a shemale's ass cheeks (lots of lube) because she said I was way too thick to go up her ass. We were really getting into it and the next thing I knew, I was balls deep up her ass. I froze because i thought I broke her ass open. After a few minutes, she told me to fuck her ass (the pain was gone) and she blasted off in the sheets from my ass fucking. After that, I would do the same thing, fuck her ass cheeks till she she thought she was ready, then I would work it in her ass.