Sts

It’s an abbreviation for ‘Swear to Satan’

What unreligious people use instead of stg ( swear to god )
by Backwards December 25, 2017
mugGet the Stsmug.

backwards

A word used, usually by fools, to tell people they disagree with them
You must be backwards if you don't think like me
by Backwards February 01, 2004
mugGet the backwardsmug.