Their use of music as meta, passive aggressive commentary to express how they are feeling was interesting. And she chose the song "Get Rid of Him" with the lyrics:

He is the one who'll tease your cryin'
He's only out to break your heart
Him with his cheatin' and he's lyin'
He's gonna rip your dreams apart

Previous moments in their fight touch on faithfulness, but it's never outright said that he (or she) cheated. So was this song choice confirmation he previously cheated or was it picked because 95% of the lyrics worked and it also happens to reference cheating?