A shitty yet still constantly used phrase developed by audio wizards who use sfm to make funny videos where random things happen and people either die or something really stupid happens. The character who utters painus in the anus is preferably soldier but if enough effort is put into it the other characters of the game tf2 can be made to say it in the Source Film Maker program on steam.
" I have a Painus in the Anus" - Red Soldier
by Not ya BOI December 8, 2017