I didn't think you could romance the teacher, well not 'officially'?
Other confidants come up saying "Choose your words carefully" when you're getting the option to commit to a relationship. It never came up saying that with her for me. There was dialogue choice which could have been considered you telling her I guess (I didn't pick it...) However, considering it doesn't warn you, I can't imagine the game thinks that it's a romance 'officially'?
It does come up, which is why I am saying she is the best romance because it's so good to do something so dangerous also her bikini outfit oohhhh boy