Sounds like they are both very young. Or at least very immature anyway.
Thats pretty obvious! If he wanted real revenge, I don't think ebay will really affect her world. Printing pages out of it and posting them somewhere she would be mortified would work a whole lot better
Well then there's nothing left to do, but fluck your sister-in-law...
Yeah, but two wrongs don't make a right. But who knows, maybe the guy and sister-in-law will work out and so will his brother and ex-girlfriend so it'll be a better couple than if they stayed in the relationship they were in!