Used instead of profanities when expressing disappointment over a circumstance.
Bob yelled “fart muffin” after hearing he lost his job.
When a male or female takes a dump in a slightly larger persons belly button (a person that may have a muffin top)
Man: Yo Steve, I just gave Susie a fudge muffin last night!
Steve: dude, you're nasty!!!
Picking up after your dog while walking it and putting the poop bag in somebody’s mailbox.
Let’s give that jerk Schmedlapp a Mexican mailbox muffin.
The female equivalent of road head.
Man, I'm glad she wore a skirt so I could give her a little road muffin on that long drive.
the act of crushing (putting all your weight on) a woman's vagina during sexual intercourse (usually applicable to an obese male)
"So, Sheila...How was it last night?"
"It was so horrible, he was a total Muffin Crusher!!"
"Damn Girl! How's your Muffin' feel right now?"
"Totally Muffin Crushed"
The resulting visual following the act of 'buttering' a partners hemorrhoidal rose bud (muffin hole).
Then the act was finished; they had a glorious muffin hole.
Smearing a bran muffin between a pair of ripe pussy lips, prefferably ones that smell of urine and cabbage.
I gave the waitress at the diner a clunge muffin last Friday and she put it back in the display case.