What is Clam Sandwich?
1.
When two women lay down, one on top on the other (missionary style). They then push their vaginas together and the male(or for lack of male, third woman with a strap-on) comes in and fucks the spot in between them. This stimulates the clits of both women and the male's penis at the same time and everyone has a great time.
Guy 1: So I heard you banged Susan and Candy at the same time last night, you pimp!
Guy 2: Yeah, I got them both drunk and had myself a clam sandwich.
See
2.
Two vaginas are pressed togther with a thin layer of roast beef placed in bewteen! It is a thinly sliced lean roast beef pressed between two hairless clams.
Excuse me... is that a clam sandwich that you two lovely ladies are displaying? Yes, we are pushing our pussies togther and, yes, this is roast beef inbetween!