Lady crush

So I’m in a very committed relationship with a man and I have the biggest crush on my sorority sister. She’s so amazing and just makes my heart melt. Tonight I learned that she also has a crush on me too. We can’t do anything since I’m dating someone and it’s a sorority rule to not date your sister but I just want to kiss her so badly. This is so frustrating because I don’t want to break up with my bf because I do want to marry him and I’m madly in love with him but I can’t stop thinking about this girl.