Oh God this is depressing as f***.
I remember
@cocohot used to constantly patronise us about how we take insults and don't stand up for ourselves, instead we cower like little whimps. When questioned on what his "witty comebacks" were, he did give one, which was awful, when he brought it up again some time after, he refused to give me any further ones.
Why? Because it's impossible, or very very rare any guy can achieve such a come back and not look like a total tool.
It's likely that any come back you give, regardless of how tame, you'll look overly aggressive or defensive "lol that bald guy has issues".
If you somehow manage to not seem ultra insecure and defensive, it's highly unlikely you'll actually say anything funny in response, you'll just look like a dick.
I think Coco's response was something like "that's not what your mother thought last night" really? Does anyone think a crowd of people will laugh in your favour at that?
The only possible solution:
Do not acknowledge it, do not entertain the joke, do not get frustrated or angry, simply move on. The best you can hope for is that people are realising it's a touchy subject for you, and you're being somewhat dignified by not getting mad and moving along and ridding of the bad moment.
Is that cowering or being a doormat? Call it whatever you want, it's not only the best possible solution, it's the only possible solution that doesn't make you look like an a**h** who's either aggressive, or trying to be funny and seriously failing at a very critical and memorable moment.