You hit the nail squarely on its head. Guys, black or white, have a fear of anything getting near their anus. If something happens, even the slightest bit of accidental something, and they enjoy it, every alarm in the guy's macho attitude brain goes off. His fear of being or turning gay is that strong. Why is that? It's because they don't know what's happening. They don't their bodies. It's because they don't even know that they have a prostate, which is an essential part of their orgasm and pleasure. I'm thinking about men mostly under 45 as I write this, because about that age, many men are well-advanced in the inevitable, natural reduction of their testosterone levels, which peaked in their early twenties. They are experiencing diminished libido, and they might be having ED or other problems. Age 45 and up, and not performing to their satisfaction, off to the doctor they go. Doc orders the necessary tests, and the guys they find out -- very likely for the first time -- that they have a prostate, which likely would benefitted them/it, if it had been massaged at least occasionally.
Information among Gen-exers and Millenials is better, but the fearsome macho myth is a hard nut to crack. Guys simply refuse to like things that they think they shouldn't, especially as regards physical contact. That's what their fear tells them to do.