I think my gf has a crush on her teacher

19(M) 18(F) Well my gf is still in high school and takes English class after her class finishes and 1 suspicious thing is that she told me her English teacher is like father to her ( she still hates her father after her parents divorced) we are in a long-distance relationship too it's fucking ass. And I asked if she was attracted to him, and she said A LITTLE. that's when i started losing myself . How do I convince her to make her realize it's wrong. I know she won't cheat on me. The only thing that bothers me is that she might break up with me if her teacher starts to like her sexually btw my gf is very sexually driven person. She told me she dreamed I was raping her which was weird but yeah how can I approach her safely I really do love her we have planned our future she is going to live with me here in September pls anything

sorry English is not my first language