No, the scene is with Dippett and had nothing to do with Dumbledore, you can Google it. Gotta say (again) your reasoning for him being gay means he was a dick to Tom (which was substantiated by him literally torturing small children) makes zero sense. Maybe read the books again because you're misremembering a fair bit.  Also, a saying "I'm a bit of a fag hag, I like gay characters" would be seen as pretty gross to gay people, ngl. You can enjoy his sexuality reveal for the added romantic depth it adds to his character and history with GG, and the reveals that are coming in the new Fantastic Beasts, but just the fact that he is gay doesn't make him more interesting. This conversation is a bit bizarre.