Definitions by UrbanSilverFox

pia sex 

PIA - Penis in ass sex (TLA/three letter acronym).
Cf: PIV - penis in vagina sex.

These are common TLAs on 'Adult' dating sites, etc.

"Not asking for PIV or PIA sex here, so don’t insist."

pia sex by UrbanSilverFox October 14, 2014