Sex, Should it Be a 'guilty' Pleasure?

I don't understand guys who feel 'guilty' about the kind of sex they enjoy. I mean, as long as it doesn't involve children, animals, or other defenseless beings, sex exists to be enjoyed, right? Sure, for the breeders out there, procreation is also high on the list of reasons why sex exists, but I think even they are supposed to enjoy it when they do it, aren't they? I used to have this friend. His idea of 'great' sex, was to go to a park (one known for its cruising environment) and blow as many guys (ideally in groups) as he could, all they while they (the blowees) calling him, 'bitch', 'boy', 'whore', etc. Then, after being 'humiliated' in such fashion, he'd go home, drop into a deep depression, and I'd get a call from his boss saying, "Patrick hasn't been to work in 3 days, can you go and check to make sure he isn't hanging from the curtain rod for me please?" Okay, I get that wanting to be a bukkake bitch in a public part may not be the healthiest of sex acts, but clearly this kind of sex 'did' something for him. It was cathartic or therapeutic, or heck, at least while it was occuring, just plain fun (for him, anyway). Don't you think we all have enough stuff to be depressed about, without doing something we 'enjoy' and then feeling unhappy with ourselves for having done it? I mean, what is wrong with a consenting adult, having sex in a way they enjoy, with other consenting adults? Nothing, at least not as far as I can tell. It seems like a complete waste of time, energy and effort to express oneself as a sexual being, and then feel bad about it later. I just don't get it.