Frasier Easter Egg - Bulldog in-Joke

In the episode where Frasier is dating a psychcology student, Bulldog Brisco starts hitting on her in his usual sexist way. She later says to Frasier that she thinks that Bulldog might actually be gay, and overcompensating for it with his chauvinistic behaviour.

This is an in-joke, as the actor who plays Bulldog, Dan Butler, is actually gay, despite the fact that his character is far from it.