Green’s Dictionary of Slang

bite my ass! excl.

also bite my bag! …butt! ...shite! bite the back of my bollox!
[ass n. (2)/bag n.1 (1a)/butt n.1 (1a)/shite n. (1)/ballocks n. (1)]

(orig. US) a general excl. of contempt or dismissal.

[US]F. Elkins diary in Elkins Heart of a Man (1973) 73: Cdr. Angel called air ops on the squawk box and led a rousing verse of, ‘Good Morning, Good Morning, How’d You Like to Bite My Ass!’.
[US]D. Jenkins Semi-Tough 185: Bite my ass, Puddin. You haven’t been off your belly all day. Sixty-four’s all over you like the crabs.
[US]S. King Different Seasons (1995) 456: ‘You’re going to wind up in traction for this!’ ‘Bite my bag,’ Chris told him.
[US](con. 1970) S. Wright Meditations in Green (1985) 49: ‘Well, bite my butt,’ he mumbled.
[Ire]G. Coughlan Everyday Eng. and Sl. [Internet] Bite the back of my bollox (phr): stop bothering me.
[Ire]O’Byrne Files: Dublin Sl. Dict. [Internet] Bite my shite phr. Feck off [...] No way.