Green’s Dictionary of Slang

p.m.o. phr.

[abbr. pissing me off]

irritating, annoying.

Urban Dict. 🌐.
[US]C. Eble UNC-CH Campus Sl. 2011 8: P.M.O. — pissing me off exclamation of annoyance or disapproval: ‘I heard they are cancelling the show. P.M.O.!’.