I just had an epiphany last night, in the morning I birthed this monster. I sincerely apologize. It was never meant to be THAT suggestive when I first wrote it.
Coffin: "Are you sure this is the best idea?"
Briefcase: "Don't worry, this is a brilliant idea!"
Coffin: "Fine, I'll open up for you. Do you really think you'll fit?"
Briefcase: "A'Wow, you're tight in there."
Coffin: "I'm not joking, but you're quite large for me y'know?"
Briefcase: "Haha, I'll fit in just fine. Just let me slide in slowly."
Coffin: "Mmph, you're edgin' me, get inside of me already mate."
Briefcase: "Fine, fine, humph! Ah, Just hang in there."
Coffin: "Bollocks! Agh—Ngh... you're one of the biggest clients I've taken."
Briefcase: "Alright there? I'll switch positions for you if you're uncomfortable."
Coffin: "... Don't, or else you'll reveal our cover."
Briefcase: "It's quite steamy, yeah? My glasses are getting a tad hazy." [Moves a little]
"There, that felt better."
Coffin: "Hm. Yes, I agree."
Briefcase: "You're really good at this, huh."
Coffin: "It's my job, I'm already used to sentient bodies inside on me. They don't remain static."
Briefcase: "I see! I love knowing more about you."
Coffin: "Stop with the teasing, love."
For context: Briefcase is going undercover, he does this by going inside of Coffin. I'm conflicted if this should go into my fanfic or not, maybe this'll be a snippet.