Happiness♥

Mum,that 3rd sister have boy friend edi.This is her 2nd boy friend.Just now,I saw her phone.Then her contact name got a love.after I saw that,Iask her who's that?Izit your boyfriend.Then she admit without thinking twice.I'm shock that because that is her 2nd boy friend edi.Should I tell you? Or I should help her keep this as a secret? She're still small,I'm scare she'll give that guy lie without telling her.Is that is a horny guy? I also don't know.Then what should I do? She is calling me keep that as a secret.Once I say out,She will never tell me next time edi.If next time she got another boy friend again,I don't think so she will tell me honeslty.I have told her don't simply accept a guy who have a nice look as well as playboy.However,she seems like don't care at all.Arghh.I think I should tell mum,But I how to tell ? Face to face tell ? Or write a letter for her? Hmm~~~~ Have a haven't mature sister is quite trouble huh.Someone help her and help me too~