Billy's so baby-faced, and hasn't changed (well, very little) since the 80s. He looks wrong with a beard now (though, if it were anyone else, that'd be a good look).
I've had a beard about four times seriously, because I hate shaving. But I hate the hassle of keeping a beard tidy even more, and Butterfly doesn't like being scratched when I kiss her, so it ain't gonna happen again.