If a person says anything about your mum just say "shut up,you will be never the man your mother is" or if they say you have a small dick just say" your just mad because your mums got a bigger dick than you"
Anyones calls you a fail just say "so was your dads condom" or "yeah, well so was your mums abortion".

If you've got any comebacks put them in the description and I will add them

Also I don't take credit for these I got heard these from my mates