My sister is making me depressed

[Karen]

Certainly talk to your parents. If you can, talk to your sister seperately, tell her you are worried about her. You don't need to mention hearing that she had sex with him, specifically, but do tell her you are owrried about her, and her choices. Don't push her to go back to the old boyfriend, she's too young to settle down longterm with any one person anyway.

[catnapper]

I think you should talk to your parents. They might need to hear it from someone else -- confirm their own suspicions. She WILL hate you for ratting her out, but it could also be that she's calling out for help.

[shihtzulover850]

tell your parents definetly!!!!! you need to. It is for her own good!