Oh My Shit 

An exclamation that combines the emotions of:
1) Oh My God!
2) Shit!

Usually used when you are feeling both of those things simultaneously...

Guy #1: "Dude, I just bought myself a brand new H2".

Guy #2: "Oh My Shit! Have you lost your fucking mind? That gas-guzzling monstrosity is such a limp-dick-mobile!"

Oh My Shit by Migrant Mind October 15, 2004

Oh My Shit 

Abbreviated to oms, Oh My Shit is said when something unexpected and unfavourable happens. Commonly followed by wtfbbq.

While riding his bike with one hand while holding his new vase in the other, John was hit with a fridge, knocked off his bike and broke his vase.

"Oh My Shit wtfbbq, who threw that fridge at me??"

Oh My Shit by hotchickens October 4, 2009

Oh my shit! 

term used when "Oh my hell" just doesnt suffice.

"Oh my shit!" last night was crazy! You were totally twisted and dancing on the bar.

Oh my shit! by mellsbells November 20, 2010