My mom doesn't like my crush, what do i do?

Ok, so i've known this guy for like 3 years now. We spend Christmas and Thanksgiving together and hang out a lot. He got in a fight (well it wasn't really a fight more of a debate) with my mom about school (he goes to southwest which is the biggest rival of the school my mom went to) and she hasn't liked him since. I know that the fight was stupid and he does 2 but my mom doesn't get it. I've tried talking to her about it but she just doesn't like him. I know he likes me but im afraid 2 ask him out because of my mom...... what do i do???