High School Homewrecker

The other woman but high school age. Someone who breaks up a dating/romantic relationship with the intent of having one person for their own.

I mean, yeah - I'm into him, but I'm not gonna let him find out! I mean he has a girlfriend and I ain't about to be a High School Homewrecker!

What is up with Stephanie tryna steal all our bfs? She might as well have 'HSHW' tattooed on her forehead!