A/N:This story was based on this prompt given to me on tumblr: "Martin and Arthur. Submarine.".
"Have you ever been in a submarine?" Arthur asked out of the blue. He was waiting for Martin to finish gathering his things before they left.
Martin blinked, not sure he'd heard the question correctly. "Erm, no, Arthur. I haven't."
"Oh, that's too bad. It's brilliant."
"You've been in one, then?"
"Well," Arthur began, "no, not exactly. But I've seen them in movies, and they look like a lot of fun." He approached the captain's chair, glad that they were alone. "Do you think we'll ever get the chance to ride in one?"
"I don't know, it seems unlikely."
Arthur nodded, putting his palm against Martin's chest. "I've always wondered what it'd be like to have sex on a submarine."
"A-Arthur," Martin stuttered as his face turned red.
"It's always been a fantasy of mine, but I never imagined it with a specific person." He locked his eyes on Martin's. "Until we-"
Martin cut him off with a kiss, pulling him by his vest, smashing their lips together. "Arthur," he said after pulling away, "it is highly unprofessional for you to work me up like this here…"
"We should go, then," Arthur suggested. "I'll come early tomorrow to finish cleaning up."
Martin nodded and led them off the plane. He pressed him up against his van and kissed him some more, unable to wait until later. "Maybe we can look into the submarine thing,"