Killer tries

Horror smacks him

Y/N tries

Horror allows it (might even be blushing)

There’s a lot of room for pining and angst here, from both sides.

First we have Flambae, who starts out deluding himself that Robert’s a rare exception to the rule, and then at some point becomes fully aware that he has feelings for him and just doesn’t want to risk losing him if he comes clean.

Maybe it’s a running joke among the Z-Team that Robert has terrible luck with relationships. Maybe Robert himself has made some casual comments that he doesn’t have the time or emotional bandwidth for romance. Either way, Flambae has gotten the signal loud and clear—Robert's not looking for anything deeper than sex, and Flambae would be fucking stupid to think otherwise. 

And then we have Robert, who does genuinely start seeing Flambae just for the great sex—until he starts developing actual feelings for him and immediately gets the sinking feeling like he’s fucking things up yet again.

Maybe Flambae talks a big game about all the guys on his roster, so Robert assumes casual sex is something he does a lot. Maybe he even thinks that Flambae’s still seeing other people on the side, and he hates the very idea of it, but he doesn’t feel like it’s his place to ask him to stop. If he’s being honest with himself, maybe he also thinks that if he asked Flambae to choose, Robert wouldn’t make the cut. 

So there’s just this constant miasma of guilt and insecurity hanging over both of them, and it makes them act a little toxic—Robert emotionally withdraws in an attempt to both protect himself from hurt and keep from ruining a good thing, and in response Flambae overthinks and spirals and gets super jealous of anyone he perceives as competition.