I realize this is an obvious and well trodden joke to be using for a punchline, but I hope the context redeems it and makes it funny again, with the callback to the “crude analogy” line working an initial punch.  This strip was written in the middle of a distracting personal mess while traveling, and I was lucky to be able to get one done at all.

Also, I had to call this “Dragon and Person” because I have no idea, even when looking at the art in huge blowup, whether the person is a woman or a long-haired man.  When you’re doing a joke about penis size, that does matter.  O_o  Wording it with no hint about the gender of the person was an extra little challenge.