I once saw a real, quintuple-vaginal-penetration porn video. I am not kidding: there were 5 penes inside of one vagina. Now, the fifth guy's penis was in the middle of all the others. He was literally rubbing against nothing but other penes. Would he have to be gay in order to do this? Could a straight man possibly be aroused by this?
P.S. Due to physics, to be able to fit all 5, there were lots of man-to-man contacts, and lots of manass in manfaces.(Edited 49 seconds later.)