An invitation to dent is someone's action or inaction that causes you to want to dent either them or their favorite vehicle. Or both.

Example: This morning at Dunkin Donuts, I parked in the last actual space, the closest one to the door. (and no, it wasn't handicapped, I don't stoop that low for parking) Basically, there's just a concrete walkway between the front door and where my car was parked. Anyways, so I come out of Dunkies with my coffee and someone has parked me in. Like a complete MORON, this guy illegally parked diagonally across the back end of my car and up onto the sidewalk. Let me illustrate for you below.

|my car| \
*--------*  *

What a dick. Anyways, so I start backing up, and such, until I finally make it parallel to his car. I look up before I make the final backout, and there's this 6'10" BIG guy the size of a refidgerator carrying 4 coffees in one hand standing in front of my car. "What the FUCK are you doing?" he hollers at me. "You fucking asshole, you can't drive worth shit!"
I reply, "You're the asshole, buddy, you can't PARK worth shit!"
He starts getting into his car and I pull back into the parking space. He yells at me again, "You little faggot, you look like a fucking faggot!" and with that he slams the door, and backs out, up the driveway, and into traffic. I shake my head and the 30-ish businesswoman sitting in her Toyota in the space across from mine shrugs and gives me a look that says, "No, I don't know what was wrong with that guy either."

THAT, my friends, was an invitation to dent. BOTH him AND his car.

And for the record, I am wearing an olive colored cotton long-sleeved shirt, brown Old Navy drawstring shorts, and my favorite pair of Birkenstocks. I hardly think that my outfit makes me look particularly flamboyant. My car isn't a particularly "girly car" either, I drive a '91 Saab 9000, arctic silver. What a yutz.