u/DysfunctionalHuman13

A few days ago I found out my younger siblings are saying slurs and calling people the n slur online in a game chat. Both siblings aren't even in their teen years, and are still rather young kids (between 9 and 13). I told them both that that sort of behaviour is incredibly unacceptable, even at their ages. When I was a kid I never would've even dreamed of saying such a thing? They've both begged me not to tell our mum, and I've agreed for now, under the circumstance that if I find out they're doing it again I will go to her. But I'm not sure what to do. I'm very tempted just to tell her anyway. They're sneaky, and probably won't let it slip to me if they keep doing it in the future.

Any advice will be appreciated, thank you