Okay, I have a few questions on Sirius...it seems that a lot of people say that Sirius was pretty much a player when he was in Hogwarts, but how do we know that for certain?

Also, I'm writing a James/Lily fic and I was going to do the pretty much traditional Sirius-is-a-player thing, but I think it's a little too clithe, so does anybody have any recommendations for how I could possibley describe Sirius' personality?