look up any word, like blumpkin:
 
1.
Spending time with your boo. aka your boyfriend or girlfriend.
Tina couldn't hang with us because she was booed up.
by Dana Dane June 03, 2006
 
2.
In a relationship, esp. in the manner that the two involved seem joined at the hip and don't do anything that doesn't involve each other. This can potentially irritate friends.
I don't check for a lot of the homies anymore. They're all booed up, so it's a waste of time inviting them out.

My boy gets booed up and starts actin' brand new. Everything's "my girl" this, "my girl" that. Disgusting.
by Kuahmel August 29, 2008
 
3.
Currently seeing someone; in a relationship; the act of already having a "boo".
Q: Do you have any friend my homeboyss can kick it with?
A: Sorry, all my friends are boo-ed up.

by Franklin I Hustle August 16, 2007