When you are going to marry your girlfriend/boyfriend someday his/her best friend will also become your best friend.
"Yeah, but you'd go to jail dude, she's FBF"
Also see Nottie.
"Her damn fbf wont leave us alone."
Type your email address below to get our free Urban Word of the Day every morning!
Emails are sent from email@example.com. We'll never spam you.
Log in with Facebook to save your favorite definitions
and share them with friends.