This guy is being so mean and making fun of my mom. :"(?

So this guy lets call him A.

He is usually a mean guy, i mean he is mean to other girls but he teases them you know sort of like fun and mean and so like years ago i hated him and he hated me it was war and i got suspended because of him but still, i got suspended for throwing his jacket in the girl's toilet because i had enough and he was hurting me so bad i seriously cry. But anyway after that its been cool with us and we been being okay and he makes me laugh but i don't like him and he doesn't like me. But i wouldn't call him a friend yet.

Anyway so i hang out with a group of friends i don't hang with them like all the time just a couple of times and they hang around A and A's other friend who i am also cool with but A's friend is not mean to me or anything he is nice. Anyway so A has a lot of different moods to him he can sometimes be really funny and nice to me and sometimes out of nowhere he is an ******* and makes my eyes water.

So anyway one time A just out of nowhere said something mean about my mom like ''I ****** your mom last night and she loved it she was screaming so loud the cops came" and i said ''no. you ****** your mom'' and then he was like ''NO! Your mom is so ugly and i ****** her and she couldn't get enough''

and my group or friends or whatever just looked at me and their faces were like ''oooh'' sort of like a ''are you going to punch him in the face'' face.

It really hurt me. I am so sensitive like seriously i cry when a guy just says i'm ugly or i'm dumb. I'm a emotional and really sensitive person. The next time he does it should i warn him? Whats a good comeback to say to something like ''I ****** your mom last night and she loved it'' or something mean about my mom.