Tell me if I'm being too strict.

I think we have a problem with my stepdaughter. She's 12, and soo into boys. She had a "boyfriend" that ended up causing drama with girls calling her a slut. So they broke up. Now she's dating his cousin. Today she comes home from school asking me how to break up with him because she doesn't know what to do about this other guy she likes.

I lost it on her. I think this is ridiculous for a 12 year old. Am I wrong? How do I help bring her back to reality?