look up any word, like tinder bombing:
 
2.
is when you see an ugly person that has some how made themself look attractive through clothes, make-up or other non-plastic surgery enhancement. To test this on someone after a few cocktails (less than three) consider if you would park the love rod in the ham wallet. If yes: "I can't beleive its not butter!" - if no: see fugly.
"Wow, have you seen what Sally is wearing? She's sort of cute now."

Yeah, I know! I can't believe it's not butter!
by prosebrosproductions June 17, 2010
 
1.
The exact opposite of a butter face. A girl who has a great face but not a good body.
I diagnosed myself with I can't believe it's not butter! I so need to start working out!
by Kaydaymuchluv81 December 01, 2011
 
3.
Insult used with somebody's name, used if the person has man boobs
"Whoa, you see that guy's man boobs?"

"Yeah, I can't believe it's not butter"
by The Teacher, PhD in swearing July 15, 2009
 
4.
when you cum on a girls back and or bread then spread with a butter knife. She then eats the bread on her back you lie down on her back and you get stuck to her.
i did a i cant believe its not butter to my girl last nite.
by tkifr March 02, 2008