Taken slowly with the right understanding person, it can be fun you never imagined. Taking a dick up one's hole can be exhilarating for both men. It creates a deeper bond than sucking and jacking off.
Yes, I found that the Corps hardened Marines, when in a pickup situation, oftentimes after sucking my dick, would want me to fuck them. I, of course, complied. Since they didn't get fucked often, I would open them up with finger play, and when they were loosened, about three or four fingers, I could easily insert my dick into their asses. They would moan and jack themselves while I fucked them. We would try to cum at the same time. The scenes were hot. Some of them wouldn't even play with themselves; they would let me fuck them to the point of their orgasm from their prostate. They were heady days back then.