What is Bun You?
1.
A person who has no more patience for you
"Man bun you."
See
2.
The expression of saying 'allow you'....When you can't be bothered with someone....It can also be used as a reply to an insult
1)'Your a waste'
'Bun you!'
2) 'Hey girl can I have your number?'
'Bun you!'
See