Glad to see you around again! Coming back in with a banger too, hell yeah. All of the choices are quite compelling so I'll do a little blurb for each one. Sniper's at the very end.

Scout (hiya c:): Probably lays into Spy the hardest, citing Spy's abandonment of him and ma when he was little as the backbone of it all. Then them meeting again decades later and Spy acting like he didn't recognize him. To be fair Scout didn't recognize Spy at first either, but the guy is practically covered from head to toe and he was little! Really emphasizing how pathetic Spy is. Especially when Spy isn't saying anything, neither to defend himself (not even physically) nor to admit his mistakes. "What, not gonna say anythin' pops? Not gonna try to be the smartest guy in the room? Not even a sorry? Shit, ya shoulda at least apologized to ma!" While knowing full well that wouldn't change much of anything. Bonus points if Spy is also into Scout, and Scout at least has a sneaking suspicion. Calls him a disgusting pervert, an incestuous bastard, having feelings for his own son (that he abandoned, Scout constantly loops back to), finally asking if the reason he's not saying anything or trying to stop him is because he likes it. Spy finally shows a reaction by shedding a single tear. Maybe Scout notices the boner and gains a second wind to make fun of Spy all over again.

Soldier: Ooh you're so right, Soldier would be perfect to push Spy around as well. Especially considering The Amazing Interrogation lol (which I know is not canon, but it's so perfectly in-character). Soldier telling him to go back to his little frog pond he calls France, and if he's not gonna defend himself to just put up his white flag already. Combines a lot of his verbal abuse with physically shaking Spy around, throwing him to the ground, stepping on him... much like Scout. Calling him a coward and saying that at least Sniper's cowardice is beneficial.

Pyro: Entirely physical, anything they might be saying is muffled by the mask but one could imagine they're saying some very not nice things. Things that would make some COD guy on xbox live in 2010 blush. Spy doesn't understand a lick of it, but sure understands being jostled around and treated like a toy. And to his despair, he's into it.

Demo: Honestly can't see him having much to say to Spy. If anything I could see the two being rather amicable. But a drunken rant from Demo would also be fitting, "everybody bloody hates you!" waving his bottle of scrumpy around and threatening to smash it and cut him up real nice with it. Threatening to pluck out his eyes so that he himself would be one up.

Heavy: I think Heavy would keep his words sparse, quietly taking him down, usual "you are a coward" stuff while also bringing up his abandonment of Scout. Maybe knocking him to the floor while intentionally making it look effortless, just to prove his point that Spy is a little baby man that cannot handle direct confrontation. Holding him down with a foot pressing onto Spy's back, pinned like the big Heavy could easily squish if he put enough of his weight onto Spy. Only to then get up and say it's not worth the effort, walking away and letting Spy and the others process what just happen. Good thing Spy's position made it so nobody would see his hard-on.

Engineer: I could see Engie taking his frustration with the enemy Spy out on the one on his team. Logically he knows Spy is an important member of their team, and technically not the one sapping his shit. But he sees that too-familiar form with a palette swap and sees red (or blu). Perhaps Spy says something related to a not so hot streak out on the battlefield and Engie snaps, verbally beats his ass like a rented mule, maybe slaps him around a bit and threatens to use his wrench to make it extra painful, saying he'd like to hear him scream. But he won't, he can be the better man, suddenly acting like he didn't just freak out on Spy. Ending his tirade by calling Spy a pathetic snake and one day, he's gonna sink his fangs into the wrong heel.

Medic: I would imagine Medic's bullying of Spy would come less out of anger and more out of pure sadism. Not having much of anything to hate about Spy, if anything seeing him as equally as clever, but oooh does he love breaking him down. Perhaps that's exactly why, even. He puts Spy down as much as he can to bring himself up. No doubt he notices the hard-on and turns the cruelty up a notch, especially focusing on how small Spy's cock is and saying he shouldn't have any right to use it. Clearly, he hasn't demonstrated proper responsibility with how he spreads his seed. Kicking and stepping on Spy's crotch, grinding the sole of his boot into it, "thinking out loud" about how he really ought to be castrated and that he could easily make that happen right now with a scalpel. Perhaps going for other things like asking why his mask smells so awful, speculating (aka projecting) that not-so-secretly, he loves being made a mess of and put in his place, and the fact that he's letting Medic do all of this is proof of that. Conveniently leaving out that he wouldn't quite mind being in Spy's place.

Sniper: Last but certainly not least... and you're right, Sniper wouldn't get too loud at all. Hell I bet most of what he wants to stick with Spy would be growled right into his ear, barely loud enough for the others to hear. Perhaps whispering some especially hard hitting stuff. Asking if he's proud of the man he is today, right this moment, being told how worthless he is. Asking if perhaps it's because he knows it's true. There's no hiding the tent from his eagle-eyes, no matter how small, and turning it into a weapon comparison. "You call that a knife? That little butterfly knife? Figures it'd be named after an insect." Pulling out his machete, "now this is a knife." And for good measure, remarking that Spy lays it on a bit thick whenever he gets splashed with jarate, suggesting he's compensating for more than just a knife.

And all throughout it, Spy's trying so hard not to cum in his pants from the words alone.