Well, I'm 19 but I'll pretend I'm older. It'd depend on the age of the kid and possibly what they did. If it's a late teen, then no. It's going to happen at around that time anyways, so might as well let it. Although if the kid didn't use a condom and admitted to that, then I'd considering telling because I wouldn't want some nonsense of dealing with a baby that I have no interest in.