What is Buh Bye?
1.
an informal expression used to say goodbye, see ya, bye etc.
Person1: I'm gonna go now. See ya!
Person2: Alright, buh bye :)
See
2.
normally used as a dismissive for a person's comments or an idea that is unwelcome or unpleasant. sometimes used after a look of disbelief.
1)Friend: "Girl what are you wearing? You look a mess."
Friend 2: "Ooh! Buh bye!"
2)Guy (joking): "You wanna mess around?"
Guy 2: "Dude! Buh bye!"