My mom hates my boyfriend

I am not allowed to have a boyfriend, but i had 1 when i was 15 yrs old.. And rightnow that i am 17 yrs old already, we are still together. My parents dont like him but they allowed us to stay together beacause i keep sneaking out and they want to stop that. Earlier, me my mom and my boyfriend met at ghe grocery and my boyfriend was terified. After he greeted my mom he told me that my mom looked at him from head to toe and kept on making him feel that he doesnt want him. When my mother was gone already, he didnt say a word and was just teary eyed.. I DONT KNOW WHAT TO SAY TO HIM.. I WANT TO COMFORT HIM BUT HOW? PLEASE HELP ME. THINK OF IDEAS HOW TO MAKE HIM FEEL BETTER AND THINGS TO SAY. THANKYOUSOMUCH!