"That's only ok when I say it" means that you think you're allowed to say something someone else isn't. For example if I said "I hate my brother" and someone said "I hate your brother too" I would say "That's only ok when I say it!" (as in no one else is allowed to say they hate my brother). The second part implies that because someone is gay they do not function correctly. It's suggested that the person is so homosexual that they are almost completely useless. The third part simply means "We know you're gay, but what you've done is gayer than we previously thought you were!" If you're unsure gay means homosexual. Hope that helps!