I see. Snape lover, eh? I love all three of them. They're all absolutely fucked up and a danger to themselves as well as society - they deserve each other. Sirius was a major reason for damaging Severus, but at that point, Sirius was probably pretty damaged himself. I am not an expert on depressions, but for all I know, depressions of teenagers most often show in form of overly aggressive and violent behaviour. That would go for Sirius (who's got more than enough reason, if you look at his family) as well as Harry.

Sirius can go and shag Severus and they both let out their pent-up aggressions, and then Remus remains all mine!!! [insert maniac laughter here]