Gay people are very explicit about their sexuality. They refer to it constantly (when in a comfortable setting), they seem to make a point of consuming gay media, and they often make what seems like a contrived point of making themselves physically appear gay. A gay colleague (a cool enough guy, I feel I should add) spends all of his free moments watching homoerotic music videos like those by Queen and Lady Gaga (two of umpty examples). He even asked me recently while on Youtube, “what’s the gayest song you know?”
The impression I always got is that they’re trying to force themselves to be comfortable with it, because really they’re not. Homosexuality is a subculture, and like any subculture it needs to be conspicuously worn by members who feel a general lack of belonging.
I do not mean to criticise gay people here (but I did here and here). It’s totally understandable that many, or at least some, would feel marginalised and lost; no society is completely gay friendly yet. The other reason I don’t mean to criticise is because this behaviour might only be the gay version of heterosexual behaviour so ubiquitous that we don’t even notice it.