I lived in a frat house for three years. There were guys who were hung and did what were termed "sport fucks" where they'd leave the blinds open so others could see them fucking girls. Personally I never saw it. One roommate did it (dammit I wasn't there) and it was legendary among those who witnessed it. I did "hear" lots of sex though as the walls weren't very thick, even with decades of paint, smoke and beer.
It was sort of accepted that anyone who was gay sort of drifted off campus where they could do whatever they wanted without notice. As long as no one saw it directly, I think a lot of the guys didn't care. However, bring it into the house and being in the late 1980s, that would have been recipe for getting kicked out. There was no political correctness or acceptance if confronted with the issue. Very prudish and closeted in many ways.
Lots of communal showers though - saw all sorts of penises - huge to small and in between. Saw some guys in the showers in the early AM with erections - probably because they didn't think ANY college student would be up at 6 or 7am unless they were drunk. But otherwise, it was just a shower.
I did recall a night of nude volleyball with a select few "little sisters" being the referees. They were gawking left and right and generally staring at everyone's packages for all it was worth. I think some of the guys enjoyed it and tried it on other nights but it didn't become a habit.
Pledges were physically challenged frequently, but no elephant walks, no sucking a pledge brother off or anything remotely like that was ever forced on anyone I ever saw or heard of. One night there was a contest to see who had the biggest dick in my pledge class but believe me, it wasn't porno-worthy to witness. Now, the guy who did win, he was a freak. Skinny and had about an 8-9 inch dick when erect. He was one of those guys who showered early so that he wouldn't be bothered by everyone gawking and asking questions.
I agree that in the "old days", the reality of the frat house was nothing like what you see in gay porn set in "frat" houses. At least in my experience.
I did hear of one guy in another frat getting caught during summer school fucking another guy...the house was empty and some alumni came through to inspect for summer time repairs and viola...a free show. It didn't go over so well with the alums or for the frat guy. He left school and went to California.
So overall I'd say like a lot of things, fantasies are better left uncompared to reality.