There’s a girl at school….

I understand you completely.It happened to me 2-3 times.But,bcz i didnt know what to do,i havent done anything.If you are shure that she is straight and that she loves him,somehow you should move your emotions a side.What helped me,is that i usually try to fall in love with someone else,but these feeling for that 2-3 girls are still here,but they are really weak now,bcz time passed.My advice is that you should try to focus your emotions in some other direction,for some other people,and just let the time pass.And you can always enjoy your time spent with her,even if she doesnt know how do you feel about her.It is hard,but if there are no chance that you two can be together,you'll have to move on.

i get where your coming from, and its important not to TRY to break them up, especially if she loves him. if you are sure she loves him, then just ignore your feelings a little bit. if they break up and you still like her, then you can casually tell her, but if she is 100% straight, and you just know she would never go for it, focus your feelings elsewhere, since tellin gher could make her feel uncomfortable around you.