Half a-don 

Not a hard-on but half way there "half a-don"

Girl 1: omg thought he was fully keen never got past half a-don girl 2: well definetly wasn't don-key

Half a-don by Redbeard89 October 8, 2011

I don't give half a fuck 

To care so little about something that one half of the standard fuck will suffice. Used when you want to make clear that you truely could care less.

Mary: "Do you want to go have sushi or steak?"
Joe: "Whatever, I don't care".
Mary: "Or should we go to Benihana?"
Joe: "I don't give half a fuck! Let's just eat!"

I don't give half a fuck by Jumpingrat September 2, 2008

I don't give two and a half shits 

You really, REALLY don't care about what someone just told you.

Brody: Hey, I just found this really funny video I wanna show you, it's about this-

Ryan: I don't GIVE two and a half shits, alright?!

I don't give two and a half shits by MCGONN June 17, 2009

I don't give two and a half shits 

Combining a reference to two and a half men and the fact that you care so little about what the other person's saying.

-Hey, guess what I was doing last night?
-You know what? I don't give two and a half shits!

I don't give two and a half shits by Deathgleaner May 24, 2010