I'm thinking Arby's 

a thought that pops into one's mind before eating extremely beefy pussy

Right before performing cunnilingus on a woman, if she has extremely beefy flaps, her male lover might think, "I'm thinking Arby's."

I'm thinking Arby's by Justin crazy May 27, 2008

I'm Thinkin' Arby's 

A phrase you utter when you see a woman whom you suspect of having beef curtains. (A play on a popular food chain's slogan.)

Newscaster: "A 60 year old prostitute was arrested today..."
You: "I'm Thinkin' Arby's."
Your friend: "Gross!"

I'm Thinkin' Arby's by SkidMarkyMark July 23, 2007

i'm thinkin' arby's 

a warning from guys to their guy friends when they see them talking to a girl who seems promiscuous or is a well-known slut, to keep them away from said girl, in reference to the girls vagina resembling an Arby's roast beef sandwich.

Sonny: "Hey, dude, I'm talking to that one Megan chick. She seems nice."
Hayden: "Dude, she's slept with so many guys. I'm thinkin' arby's."

i'm thinkin' arby's by sonnyreyes August 4, 2008

I'm Thinkin' Arby's 

1. A phrase used to indicate one's negative feelings regarding a proposed situation.

2. A courteous declination to an unpleasant proposition.

Dude #1: "Hey, man. How would you like to spend a night with that beast?!?"
Dude #2: "I'm thinkin' Arby's!"

Friend #1: "What do you think about going to Kevin's place after the game?"
Friend #2: "No way, dude. Kevin's a jerk! I'm thinkin' Arby's."

I'm Thinkin' Arby's by aksival December 18, 2006