The hilarious and cruel irony is how very far from the screaming sentiment in Ed's ear Oswald is. It's not about Ed because for Oswald, like so many things, it's all about him. His own fear, his own rage, his own selfishness. The Ed across the tabling, smiling and relaxed, open and friendly--it's there to haunt and taunt him. It's a reminder of his mistakes, his desires, his failures, his selfishness, his comeuppance, his fear.

No-one has known him like Ed, just like no-one has known Ed like Oswald.

"... this was a mistake," he mutters to himself, one hand cradling the side of his head with his fingers pushed far back into his hair from his temple. "I-I-I... I shouldn't have--"

This is far from what he needs to be right now. It would be much easier to deal with this with rage and fury, spitting threats and glaring down the barrel of a gun, eyes wild and daring. This is the version of Oswald that just doesn't know what to do with his feelings. Or his feet.

"I have to-- I can't--"

He makes a clumsy backward shuffle toward the door, no route in mind or plan of where to go or what to do.