What to say when youre Ex playfully but blatantly makes fun of you?

[A]

So I broke up a few days ago and she was really sad and desperate on a chase.... I won't to be back friends with her later so It can't be mean. Also it's on facebook so everyone can see it. I'm also friends with a few of her best friends and they were sad I broke up with her (they are on her side i think). So on fb one of her friends was calling me an idiot (oh yeah so b.a) and then she's like yeah he really is an idiot lol. She's not very smart herself (i'm way smarter and everyone knows)

Is there something I can say back thats also playful but is a pretty good comeback?? It can't be mean and all of our real life mutual friends (didn't know what to say xD) will see it and they are on her side!?!?!?

[Charlie]

Truthfully i wouldn't say anything. if it were me i would let them have there fun it's probaly just making them feel better...