Ok, raise your hand if The Turtles "Happy Together" is stuck in your head right now.
If you're not raising your hand after watching The Big Bang Theory Season 10 Episode 19, I'm going to assume you're lying.
We basically had two separate stories going, and for once, both were pretty equally funny.
Sheldon and Amy have never been the most conventional couple. How could they be? For one, that'd be crazy boring, but besides that, they're just completely the opposite of conventional.
We've seen them make strides in their relationship, but we've never really seen them work together professionally.
As a physicist, Sheldon has never thought too highly of Amy's biology background, and while they are both scientists, they've never really had a reason to collaborate before.
It all started with Sheldon telling Amy about his work, redacting the classified portions with well timed honks of her car horn, much to the annoyance of every other driver on the road.
Amy, in turn, told Sheldon what she was working on, and surprisingly, Sheldon actually took an interest in it.
In order to work together, ground rules had to be established, but when that didn't work, they literally went out the window (which didn't stop Sheldon from recovering his tossed notebook).
Eventually a decision had to be made.
Would they risk sacrificing their relationship in favor of science, or would they put their relationship first?
Of course, they couldn't even agree on that. Duh.
Anyone who knows Sheldon would guess he'd sacrifice just about anything for the sake of science. Thus, new ground rules had to be established.
Amy: Number three, to avoid getting frustrated, we take built in breaks and award our successes with a small treat.
Sheldon: Oh that sounds fun. Now we're talking about real treats, right? Not Bible verses like my mother used to give me.
Lucky for them, they know and understand each other so well (and Amy is just so patient), that they can get through just about anything.
Raj and Penny were a whole different story.
Penny and Sheldon had a special relationship, but he was more like their kid.
Now that Raj has moved in, Penny basically has a new girlfriend, and Leonard doesn't know how to deal with it.
Realistically, he should be happy that Penny has someone around to do the things with her that he has no interest in, like shopping. But, that doesn't negate the jealousy he feels.
If he's going to feel jealous, it should be about the fact that Penny and Raj came this close to hooking up so many years ago. Remember that?
Leonard felt so left out of Penny and Raj's new bonding time that he decided to tag along with new parents Howard and Bernadette. He went from being third wheel in his own relationship, to third wheel in someone else's.
But hey, a trip to Target with a screaming baby can be fun too, right?
Leonard: Anyway, I figured I can hang out with my friends and have fun too.
Bernadette: Well if your idea of fun is riding in a minivan to Target for diapers things are about to get nuts.
Penny and Raj's matching shirts were pretty great, but I have a hard time believing Penny would ever agree on anything fashion related with Raj. They just do not have the same sense of style.
But for the sake of humor, I'll go with it.
I also loved Penny and Raj wine tasting, with a third glass right there on the counter, and then realizing that Leonard isn't actually with them. Even better was Penny calling him rude. How long was he gone before she actually realized he bailed?
Thankfully, there was no Stuart, because I don't know if I could have handled him.
Howard making the comment to Leonard about knowing what it feels like to be a third wheel made me immediately think of Stuart.
He used to be funny, and still can be in small doses, but lately he's just been getting on my nerves.
It was way more fun basically getting to see Leonard in his place.
I don't know how long Raj will be living with Leonard and Penny, but there is definitely potential for laughs there, and it's a good shake up from when the couple lived with Sheldon.
Eventually it might be nice to actually see them on their own, without a buffer, but this works in the mean time.
Considering how bad Leonard's allergies and asthma are, it's a little surprising he doesn't seem to have any qualms about Cinnamon living with them. He even took her for a walk so his wife and buddy could finish their yoga routine.
What, Cinnamon doesn't know how to do Downward Dog? I feel like Raj would have taught her all the yoga moves.
After seeing Beauty and the Beast...twice, I have to say I appreciated Howard's reference:
Sheldon: Gentlemen, the most interesting thing just happened with this spoon.
Howard: Unless it was singing "Be Our Guest," I doubt it.
If "Happy Together" isn't stuck in your head, it's probably because "Be Our Guest" is instead, right?
What did you guys think of Leonard as the third wheel? Did you like Sheldon and Amy working together? Do you want to see them collaborate more often?
If you missed anything, be sure to watch The Big Bang Theory online and catch up!
Stacy Glanzman is a staff writer for TV Fanatic. Follow her on Twitter.