The Father of Western Philosophy never had any children of his own. Seems kind of sad, especially since he's sort of obsessed with the subject. After all, he has Socrates describe himself as a "midwife" and his character Diotima speaks of the importance of "giving birth" to beauty. Was he just a frustrated dad? No, he would tell us that he produced endless intellectual progeny, which is, of course, so much more satisfying. Yeah right, Plato.
Okay, but about this gay thing: it's a little hard to know Plato's actual feelings on the subject. Yes, he does talk about the joys of gay sex—oh sorry, his characters do—but in his last dialogue, the Laws he condemns it—ahem, one of characters does. Does everything have to be so ambiguous with this guy?
Written over the door of Plato's Academy were the words: "Let no one opposed to wife-swapping enter here." Okay, we're lying. Actually, it said: "Let no one ignorant of geometry enter here." But we're desperately in need of some bit of salacious gossip here. (Source)