Muscle Man bets Mordecai that if he kisses Margaret within the week he will wear a diaper, and if he doesn't Mordecai will have to.

!!Tropes
* AlmostKiss: Between Mordecai and Margaret.
* BaitAndSwitch: When Mordecai puckers up to kiss, Margaret bypasses his mouth and goes to his ear to whisper, [[{{Troll}} "Have a nice week, diaper boy]]."
* CallBack: Mordecai comes prepared to the date with a ton of breath mints to avoid the events of [[Recap/RegularShowS03Ep39BadKiss Bad Kiss]].
* CrazyPrepared:
** Muscle Man buys an entire shelf full of diapers to prepare for who loses the bet.
** Mordecai comes prepared to the date with Margaret with a fanny pack's worth of breath mints. However, he eats [[{{Understatement}} a little too many]], [[GoneHorriblyWrong causing his breath to freeze everything around him, including himself]].
* CruelTwistEnding: PlayedForLaughs and [[DownplayedTrope Downplayed]]. Although Mordecai lost the bet and is forced to wear a diaper for a week, he is elated that Margaret had fun on her date which means he still has a chance with her.
* DisapprovingLook: Rigby, Muscle Man, and Starla give Mordecai one after his awkward hug with Margaret in the beginning.
* InnocentlyInsensitive: When Mordecai wants to see a romantic movie (in hopes to get Margaret to kiss him), she replies, “Boring!”
* NeverMyFault: Muscle Man snarks at Mordecai for revealing the bet to Margaret about kissing her, even though HE was the one who brought it up in the first place.
* PyrrhicVictory: On Muscle Man's end. Though he ultimately won the bet, he doesn't enjoy the outcome since Mordecai is too busy relishing in the fact that Margaret enjoyed her date with him to be annoyed or embarrassed at wearing a diaper all week.
* RhetoricalQuestionBlunder: When Margaret angrily asks Mordecai if he bet that he could kiss her, Rigby points out that it was more if he WOULD kiss her, not COULD.
* ScrewThisImOutOfHere: When Mordecai is about to buy a tuxedo and for his date, and he then realizes how expensive it is, he immediately changes his mind and runs out of the store.