He's not gay because none of the Mario characters are gay. Some of them aren't even heterosexual. Why? Because sex isn't a central theme in the Mario universe. Seriously, I wish people would use a little common sense before making topics like this. From what I understand, pulling out a rose (he does this in Mario Party 8) in Japan makes you a player. Of course, in America, pulling out a rose makes you gay. I'm pretty sure Waluigi came from Japan, not America. He's not gay, he never will be gay.