When two men tag team up on another man in a sexual manner. Some uses have been in reference to the private parts of a female.
I walked into a room and vomited after i saw the lamb sandwich.

In Reno I bought a round of Lamb Sandwiches for everyone.
by whatsadick4 May 28, 2008
Get the Lamb Sandwich mug.
Where you have sex in the bathroom of a restaurant.
Hey, when I'm in town you want to go get A Lamb Sandwich
by Jack Steel May 22, 2009
Get the A Lamb Sandwich mug.