Well, I never have but have to say that once, while a gorgeous black brasilian shemale was fucking me -I should say I was fucking her because I was on top, sitting on her bbc- I was on the edge of it, but I cried ohhhh gosh I am cumming! And she ordered me not to dare yet........ and I stopped moving. Nevertheless I know I am able to cum only by being fuked up my arse. That is a real story, not imagination