S2G
Swear to God
Example
S2G he had this huge black eye, and he wouldn't tell me why!

Related Slang
ISTG | I swear to God |
ONG | On God |
tru | True |
tru dat | True that |
Truth bomb | A surprising but true statement |
AAMOF | As a matter of fact |
LLPOF | Liar liar pants on fire |
Those who believe in a higher power may use S2G to stand for "swear to God." This acronym asserts that, to the best of the sender's knowledge, what they've said is true - and they'd swear the same thing to whatever god(s) they believe in.
Typically, you'll see people append S2G to unbelievable statements, to assure you they are not a LLPOF. In some instances, however, you may see S2G used not to emphasize that someone is telling the truth, but to emphasize their exasperation (e.g. "I S2G, if you blow that horn one more time ...")