1. To be made fun of or joked on in a manor that you did not expect or see coming.
2. To be blindsided because someone got you to look the other way.
"He totally stooged me with that joke.. I had forgotten about that"
"I looked to the right and then he slapped me from the left.. He really stooged me."
To lose the advantage, to be taken advantage of.
"Man that guy just took my chick. I've been stooged!"