Im trying to be friends with my ex boyfriend but my parents hate him; should i go with my parents opinion?

my parents openly hate my ex boyfriend. now he did not abuse me, but he was mean sometimes. and of course i was mean back haha. now were trying to be friends and i think its great to not hold grudges and rekindle a deep friendship we had before we dated. he even asked me if i wanted to hang out this friday. but i don't know how to tell my parents im going to because they will go on a tirade about everything they don't like about him. should i go with my parents opinions and trust their wisdom and not try to be his friend, and prevent future tirades? or should i go with my heart and try to be friends with someone i was already good friends with before we dated? thanks for your advice.