Marisol's gay BFF and so called "most trusted confidante" (4.32) isn't around much, but we see him long enough to know he's a firecracker. He has no trouble saying exactly what he's thinking, and when he first meets John, he outright asks the guy what his deal is, completely unconcerned with whether he's offensive or not.
He isn't just brash, though, and when Marisol needs a shoulder to cry on or an ear to yap into, Birdie's her guy. She calls him to talk over what happens at prom, and he gives her sage advice in return. Birdie is a great example of what a real friend is. He's honest (if not a little blunt), listens, and is always there when Marisol needs him.