"The Cohabitation Experimentation" is an episode of The Big Bang Theory that first aired on October 17, 2016. Directed by Mark Cendrowski. Teleplay by Steve Holland, Eric Kaplan and Jim Reynolds, based on a story by Chuck Lorre, Maria Ferrari and Tara Hernandez.
Bernadette and Howard intended to go on a vacation, but she's in no condition to travel on account of her prolonged morning sickness. So Howard suggests the two of them should just stay home. They don't tell anyone, so Stuart (Kevin Sussman), assuming Bernadette and Howard are gone, uses their hot tub. Raj thinks the same thing, he shows up later.
Amy and Sheldon are still living together in Apartment 4B, but things are getting fractious. The two of them go to Apartment 4A to complain to Leonard and Penny, who decide that Amy and Sheldon need a little time apart. Penny takes Sheldon to an ice cream shop, while Leonard stays in the apartment with Amy.
Tropes
- Bait-and-Switch: Sheldon tells Amy that he's ready to take their relationship to the next level. Cut to him proposing... that they share his toothbrush holder.
- Big "WHAT?!": Howard exclaims "What?!" when he learns that Stuart uses the Wolowitzes' hot tub when they're not around.
- Brick Joke: The raccoon.I told you raccoons don't say "Uh-oh."
- Cerebus Retcon: Sheldon reveals that witnessing his father having sex with another woman caused him to knock three times ever since: The first knock is traditional, the other two are to give them time to put their pants on.
- Hammerspace Hideaway: Where Stuart must have been while underwater, given that Raj gets in the pool and appears to stretch out a bit yet never notices him there. It's not that big a hot tub.
- Hypocritical Humor: As Amy sits on Sheldon's spot on the couch, she says that when she becomes more assertive she'll sit on it all the time. The moment Sheldon returns, however, she moves over before he finds out.
- I Lied: When Howard and Bernadette overhear Stuart telling Raj that he's been getting into the Wolowitz house using the house key he got when he was still living with them:Bernadette: You said you got it back!Howard: Well, clearly I lied.
- Minor Flaw, Major Breakup: The reason for Sheldon and Amy's fight? He won't let her put her toothbrush in his toothbrush holder.
- Naked People Are Funny: Stuart confesses that he is not wearing anything as he sits in the hot tub.
- Offscreen Breakup: Raj confesses to Stuart that he's single, meaning he broke up with Emily and Claire sometime after their last appearances. He says it was by choice, though not his choice.
- Pants-Free: It's only at the end that Stuart confesses that he was naked in the hot tub the whole time.
- Primal Scene: Sheldon reveals that he once walked in on his father having sex with another woman. It's also the reason why he always knocks three times; the first knock is traditional, the other two are to give them time to put their pants on.
- Rage Breaking Point: Hearing that Stuart has been bathing naked in his hot tub is what causes Howard to angrily reveal himself to Raj and Stuart at the end of the episode.Howard: (shouting) You jackasses just bought yourself a hot tub!
- Reactive Continuous Scream: Raj and Stuart scream in shock upon seeing each other in the hot tub once Stuart reemerges from underwater.
- What Have We Ear?: Howard pulls a coin out of Bernadette's toes while giving her a foot massage.Bernadette: Can you please stop making money come out of me for two minutes?
