I hear jokes all the time and it bothers me too, even from older women, I heard this 44 year old woman I know make a small penis comment once and kinda laughed about it, I think its gotten stupid and immature.
They know that they can get to us about it, especially women at that age. They’ve seen it all, and seen how insecure or at least conscious most men are about their penis size. Its a very easy way to take you down a peg or two and they do it and will continue to do it. :-(