How do I tell my mom I'm dating sombody if my mom and his mom hate each other?

So me and my friends walked uptown today to mcdonalds and my best guy friend asked me out. So we are going out. We have gone out bfore but then we got n a huge fight and his mom called mine and they faught and then they said we werent aloud to date again and it'a getting hard to keep it a secret. But i dont know how to put it into worda. How do i tell my mom that i'm dating him if our parents dont wnat us to? Please help we really like each other....