I figure each person has a situation where they really want to insult someone, but for whatever reason, are unable to do so.
So, I open myself up to your venom, sarcasm, and swipes.
Since this is MPSIMS, keep it clean, but at least make it creative.
I am your whipping boy.
Ooh . . . what a great idea. Wish I’d thought of it.
Here’s one I’ve been saving for an aquaintance of my mothers’:
“You have the attention span of a sparrow, so I suggest saving your minimal concentration powers for remembering to swallow so the water doesn’t run down your trachea instead.”
“aroint thee, thou rump-fed runnion!”
Oh, it’s you.
I didn’t recognize you since you shaved your back.
My pee pee is bigger than your pee pee.
Your father is a hamster, and your mother smells of elderberries.
You’re also a pribbling beef-witted codpiece.
So there.
:::shrug:::
You are a one-eyed goat felcher, possessed of the mental prowess of a door stop.
…and your mother wears army boots. 
I once broke up an anti-abortion rally by showing protesters a photo of you.
Jesus was in a coma.
May the fleas of a thousand camels invade your private parts.
Nice meeting you, the pleasure was all yours.
You’re ugly and your Mother dresses you funny.
You’re a fungus without culture. I just made that one up.
Your face is reminiscient of this odorous opossum I hit that looked like so much like the spawn of Satan that I backed up several times to make sure it was dead.
If you think that I would waste my 200th post on insulting the likes of you, then you are even more dim-witted than I had been told you were.
If you were on fire and I had just finished off a Big Gulp in one minute, I wouldn’t waste my precious urine to put you out.
Why, I wouldn’t cross the street to shoo flies off your rotting carcass.
I’ve known slime molds with more personality than you.
Thanks, Mullinator. I’ve been having a bad week and I needed to get that off my chest.
You dumb and
you apparently screw up my computer.
You’re such a loser, your Rice Crispies don’t even talk to you.
I can’t think of one, but you guys are funny
Mullinator, you ignorant slut.
You impotent masochist, you couldn’t get it up even if you understood Qadgop’s gibe or Eve bitch-slapped you for not having the guts to have a sex change. Just being on the same page as you nauseates me and every right thinking, normal citizen.
Urp…
You pre-cerebral societal disorder, what’s a mistake like you even doing posting on a messageboard when you should be in electroconvulsive therapy? Did someone leave the gate unlocked again?
This is the best thread ever!