Blame it on Cassidy

In a gym, Friday evening while sharing the squat rack, Mallory and Dakota discover they both had a crush on the same guy, Mason, but sympathized with each other when the find out that this guy had spurned them both for another woman. As the two were drawn together by their shared tragedy they decide to watch a movie together and drown their sorrows in Diet Coke. Inspired by the movie they are watching the two bare their souls about their disastrous romances, they are certain all their bad luck is due to some girl named Cassidy.
Plotting their revenge it's clear they need to get back a this Cassidy and clear the way for them to hook up with Mason. When the girls meet again at a McDonalds to firm up the plans for revenge, they run into another friend of theirs, Madison who insinuates herself into their plans without any idea what they are. They don't' want to reveal the real plan so they invite Madison back to Dakota's for a sleep over.
The girls have such a fun time in the end all thought of revenge and Cassidy are forgotten.