It's Always Sunny in Philadelphia: Season 2, Episode 4

2 - 4: Mac Bangs Dennis' Mom

Barbara (Anne Archer) sleeps with Mac to arouse Frank's jealousy, so Dennis decides to seduce Mac's mom as payback. And Frank's decision to put Charlie in charge at the bar prompts an orgy of backstabbing and double-dealing, with sex as the weapon of choice. Danny DeVito's daughter Lucy guests as Jenny.