Why isn't Sheldon more upset when he learns Amy has been lying to prolong their cohabitation experiment? Because just as Amy wisely deduces that a little fibbery about her apartment is required to coax her change-adverse boyfriend into making a decision he clearly wants to make, Sheldon too knows he would have dragged his feet indefinitely about making their temporary situation a more permanent one.
And that, my fellow Big Bang Theory fans, is ass. Buridan's ass, to be exact: the paradox that theorizes a hungry donkey standing equidistant between two bales of hay will starve to death, paralyzed by indecision about which nosh to choose. Sheldon is obviously the ass in this situation, after he learns Amy's waterlogged apartment was repaired two weeks prior. Both Penny and Leonard point out that Amy lied because she wants to continue to spend more time with him, and Sheldon quickly accepts that fact and begins to consider moving in with Amy for good.
But change is hard for Sheldon. The mere consideration that his old room in the apartment could become a warehouse for Leonard's collectibles (or worse, as Sheldon imagines in a nightmare, a sex dungeon complete with Leonard in chaps and Penny in control of a whip) sends him on a brief personal journey. A very brief one. It takes him across the short hallway between his and Leonard's place and Penny's apartment, where he and Amy have been living. There, he Buridan's asses himself about going back to his old home or choosing to move forward with Amy. It's only when Amy comes home and slyly leads him into a philosophical discussion on the very topic of French philosopher Jean Buridan and whether or not his paradox was ripped off from Aristotle that Sheldon naturally follows along, choosing life with her.
As most of the best Shamy moments have unfolded, this one too does so subtly and sweetly. But Miss Fowler is not the only female member of the group with some trickery up her sleeve. In a quest to de-nerd her temporary (or maybe permanent?) home with Leonard, Penny has been slowly putting his pop-culture merch into storage. She's been carrying out her plan so stealthily, in fact, that he hasn't even noticed his Batman keychain is gone, just like his wizard robes and his Klingon word of the day calendar.
It's only after a bit of blabbing from Howard, who heard it from Bernadette, that Leonard catches on to Penny's pilfering. Bernadette also spilled the beans to Leonard about Amy's lies, so all the secrets and attempts to uncover them lead to a clever scene in which Sheldon and Leonard speak in Klingon and Amy and Penny speak Ubbi Dubbi to keep their schemes in play. When Leonard finally confronts Penny about hiding his stuff, she (fake) indignantly demands, "Oh, so you believe your friend, and your friend's wife, and your own eyes over me?!"
Like Amy, Penny gets her way in the end, as Leonard finds himself with a newly redecorated bedroom. Yes, it's a very pink new bedroom, which prompts him to stash a fluffy pillow and some other pink home décor items at Sheldon and Amy's.
- Not only do Sheldon and Amy do their first-ever "on location" (from Penny's apartment) edition of Dr. Sheldon Cooper and Dr. Amy Farrah Fowler Present Dr. Sheldon Cooper's Fun With Flags, but the web series now has a house band: Raj and Howard's Footprints on the Moon, they of a little ditty you may remember, "Thor and Dr. Jones."
- And what could be the theme of such a very special episode of FWF? In honor of Shamy's living arrangement, they celebrate flags of countries that have joined themselves (and their flags) together, like St. Kitts and Nevis.
- How lonely is the girlfriend-less Raj these days? He says he's "eating-cake-on-the-toilet single."
- Sheldon: "I'm very good at complaining. If it were an Olympic sport, I'd complain about what a stupid sport it is and then I'd take home the gold."
- Sheldon says people tell him he looks like the skeleton in The Nightmare Before Christmas, which he finds both flattering and insulting.
- Sheldon's takeaway from the cohabitation experiment: Everyone wants to live with him. "I'm like a man made of sugar in a world full of ants."
- Amy discovers she can lull Sheldon to sleep by humming the theme song to 2001: A Space Odyssey.