PMAO Share definition Flag In Porn: PMAO stands for "pissing my ass off" or the act of urinating in someone's gaping asshole. -As popularized by the LegalPorno website. After getting triple penetrated, she got into kitty style position for a vicious PMAO session. PMAO by beautifulrock July 10, 2015 0 0 Get merch Get the PMAO mug. Buy Now — $32.95 See more merch