Green’s Dictionary of Slang

pain-in-the-ass adj.

also pain-in-the-arse, ...booty
[pain in the arse n.]

(US) infuriating.

[US]Kerouac letter 29 June in Charters II (1999) 366: No Lucien come yet, no Allen, just pain-in-the-ass visitores [sic], as usual.
[US]S. King It (1987) 96: He would go in style, and with no pain-in-the-ass client sitting in the back seat.
[US]L. Rodríguez Always Running (1996) 81: ‘That’s the way I talk to my pain-in-booty, so-called sister’.
[US]Simon & Burns Corner (1998) 119: The juvenile system is such a pain-in-the-ass complication for a working police.
[US]D.H. Sterry Chicken (2003) 47: My husband, that painintheassbastard, you know what he said to me?
[NZ]P. Shannon Davey Darling 173: Jesus, she was in a pain-in-the-arse mood.
[US]Codella and Bennett Alphaville (2011) 208: Having bid a clipped but polite good-bye to my own pain-in-the-ass D/O at the Housing Command [etc.].