"That's not--" he starts, then breaks off. He takes a bottle out of the fridge, shaking his head while he opens it and takes a drink, before finally turning back towards Daniel.

"You've nothin' to apologise for. M'not angry at you," he says. He doesn't even know why Daniel would think so, why he sees the need to defend himself - except of course for how Seth is acting. He's the one keeping Daniel at arm's length here.

Another thing to feel guilty about. Here Daniel is, returning from the dead, and Seth can't even treat him properly, can't even tell him he's happy to see him. He wishes he could do so with some sort of physical gesture, a hug or a grip of the shoulder, something. He really wants to hug Daniel. There was nothing left for Seth to touch after he disappeared, and there's nothing now.