To question the statement somebody has made in an effort to reveal it's validity, knowing that if they are lying the are Hell-bound.
Yønni: "I got these shoes for 11 Russian Rubels, with the laces!"
Borîs: "s2g 11 Rubels?"
The acronym for "swear to God". When asking someone a question that they may lie about so they don't get in troubke, use s2g to get them to tell the truth. If they lie when swearing to God, they go to hell, because lying to God is a sin.
Ted: Some bitch stole my car.
Tony: Man, that sucks.
Ted: S2g it wasn't you?