Gwen has Arthur drinking pineapple juice on the days she plans to give him blowjobs. He develops a Pavlovian reaction to pineapple juice and he later realizes by reading an article that it's because it makes his spunk taste sweeter.

Arthur pulls the can of pineapple juice out of his cooler bag. He stares at it, wondering why he suddenly feels… needful.

It's Friday, and Gwen packed his lunch today. She does that sometimes. Arthur lets her, never asking for her to do it. She has a job of her own; she doesn't need to be taking care of him all the time. Even though he likes it when she does.

Especially when she packs pineapple juice for him.

Though he can't quite figure out why. He pops open the can and takes a large swig. It's cool and refreshing, and he can feel it travel down his throat and into his stomach, down, coursing into his...

…the hell?

"Hey, Arthur, want some company?" Merlin pokes his head into Arthur's office, a brown bag and a plastic bottle of Coke in his hand.

"Sure, come on in," Arthur says, blinking out of his reverie.

"Something wrong?"

"Um, no, don't think so. Just thinking about something."

"Oh?" Merlin opens his bag and produces an egg salad sandwich and a bag of crisps. "What?"

"Pineapple juice," he says, lifting the can for Merlin to see. He actually has two cans, because they're small.

"Odd thing to have with lunch," Merlin says.

"Gwen packed it. She puts them in there sometimes. I think she's trying to make me eat healthier."

"Well, considering she gave you a pretty hefty slice of her homemade chicken pot pie, I don't think that's entirely likely," Merlin says, eyeing the leftovers in Arthur's plastic container enviously.

Arthur eats some of his lunch, then takes another sip of juice.

"You're blushing, Arthur. Why are you blushing? And are you going to share that pot pie or just sit there and watch me salivate?"

Arthur cuts off a chunk of pie, puts it on the lid to his container, and passes it to Merlin. "This juice is giving me… thoughts. And I have no idea why."

"Weird."

"Yeah, the last time she sent me pineapple juice was when… we… …and then there was the time… …and that other… …wait."

"Do I want to know?" Merlin asks.

"Probably not," Arthur says, setting his lunch aside while he turns to his computer. After a minute, he leans back in his chair. "I think I just solved the mystery."

"What?"

"You have to come over here, I am not reading this aloud," Arthur says, pushing his chair back from his desk as Merlin walks around.

" , hey? Got a website for everything."

"Just read. There." Arthur points.

"'…Most kinds of pineapple juice will sweeten the taste of your…' Oh, my God, Arthur! I did not want to know that about Gwen!" Merlin exclaims, looking in horror from the screen to the cans on Arthur's desk to Arthur.

"Got to give her points for creativity. And ingenuity," Arthur says, shoving Merlin back over to the other side of the desk.

Merlin stares at his sandwich. "And conditioning you like one of Pavlov's dogs," he says.

"Shut up, Merlin. Jealousy is an ugly emotion."

"What does it say on the can there, on the side?" Merlin angles his head, smirking.

"What? 'New and improved flavor.' Oh, Lord…"