hopefully im not stepping out of line here by saying this-- i have been tricked by fake suicides more than once and still am and it sUCKS-- but i still feel really ehhh about the idea of telling the kids mom. I mean if the kids faking suicide, like you mentioned there is probably Some Sort of problem that is creating the behavior, and i worry that in some cases-- not all, mind you, but you wouldn't know which ones-- the reason is the parents are abusive. so I worry it'd cause more abuse :L
reporting any wrongdoing could lead to the jerkwad suffering terribly in ways that i would object to. i’ve had too many personal experiences with this question to not have had to make a decision on the matter.
if someone says they’re going to kill themselves, they might get shot for refusing to put the knife down when the cops show up. i’m still calling 911 for them. if a family member steals my identity and racks up debt in my name, reporting them might get them thrown in prison because they’re already on probation. i’m still reporting the theft.
if a kid tells his dad that his stepfather is beating the shit out of him, he knows the entire family might melt down in a custody battle. should that possible outcome decide whether the kid reports it or not? even assholes are people. there is no such thing as a villain, and i think we have to be careful with how we as a society distribute consequences and blame when bad shit happens.
the world sucks sometimes and victimizers are sometimes mistreated in turn, but in situations where i am forced to choose who should carry the extra weight of that unfairness, my last answer would be “the victim”.