The Comfy Chair

Exactly, yes. It's not an 'error' to think that, in this situation and with these people, there needs to be something between them that's deeper than 'two guys who work together' to motivate them to have sex, to make it feel okay for them to have sex, in this weird situation. Any other interpretation feels unreal, to me, and sort of like those stories where the writer wants to write a particular kink and shoehorns her favorite characters into it, whether it's a good fit or not. It's about human motivation and interaction, not about "Rodney and John are so in love! And only with each other!" Because that's silly and unreal, too. It has to be a combination of circumstances and who these people are, what's going on inside them, for it to feel real.