the act of 2 female friends that have now been related through their vagina's after having sexual relations with the same man.
Angelina Jolie and Jennifer Aniston are cooter cousins because they both have had sexual relations with Brad Pitt.
by Licky Pee April 11, 2010
When two girls have slept with the same guy.
OMG you slept with Taylor too? We are cooter cousins now.
by Rachel Sawyer November 18, 2009