Green’s Dictionary of Slang

(US campus) a euph. for fuck you! excl.

1980		Eble Campus Sl. Fall 2: bunk you! – expression of hostility [...] Bunk you, you moron!
1996		Eble Sl. and Sociability 40: In the hostile college slang expression bunk you, a euphemism for fuck you, bunk begins with a labial and ends with two velars.