Without a doubt, sexual language is disgusting. Sex is disgusting in general. Now hold up Mr. or Ms. but I love having sex, Do you like sex with random people? Ugly strangers that aren't very clean? Your neighbor? Do like talking about bodily fluids with random people? With creepy people? If you're normal, you're probably already feeling disgusted. Sex is natural, but like pooping, it can be pretty nasty in most contexts (pooping is nasty in all contexts). So using words related to sex is discomforting and disgusting and therefore good for insulting people or exclaiming disappointment.