S5·E8 Louie's Revenge

Louie gets a call from Emily, who jilted him in an earlier episode, who is drunk and drugged and wants to meet him at a nearby bar. Louie decides to go over there to throw a drink in her face and reject her, therefore getting the last laugh. However, when he gets to the bar, Emily serenades him and has Louie eating out of her hands. The next morning, she is shocked to see him wake up next to her, but Louie somehow convinces her that they are meant for each other. They begin a relationship but it becomes evident that Louie has become Emily's slave and he's starting to hate himself for it. Eventually she comes to a realization of what she's doing to him and breaks it off with Louie, who is relieved, but he finally exacts revenge by throwing orange juice in her face.