Oyster Bash 

the female equivalent of a sausage fest

the all girls school has an oyster bash every weekend

Oyster Bash by edmondsun August 19, 2009

bashing oysters 

slang for lesbian coitus; scissoring; bumping uglies;

I walked in on my two ex-girlfriends bashing oysters the other day.

bashing oysters by theromero4 April 13, 2017