Seamus just nodded in response to Dean's greeting, the uncertainty of it stiffening his resolve. "This is daft," he said without preamble, waving one hand between them while the other pocketed his wand. "You didn't need to apologise. You were asleep. And you didn't do anything wrong anyway." Seamus didn't like to admit he was sensitive about his scars, liked to pretend his problems could be traced back to some other root - but even if he was sensitive, he wasn't so bad he couldn't endure Dean accidentally touching them. Yes, he'd scrambled out of the bed - but that had been mostly shock.
And as for the disgust... that was only natural. Seamus should have expected it, should never have convinced himself Dean could feel any other way. Dean hadn't pushed the truth on him, but that was because he was a good friend and Seamus couldn't blame him for that either, even if it was technically speaking dishonest. "I know it's been weird." No point lying about that. They could both sense the atmosphere. It would probably stay weird for a bit. Seamus wasn't going to just forget that touching him was something Dean had been forcing himself to do for years. He couldn't, if he wanted to make sure things changed now. "We'll figure it out."
Seamus tucked both hands into his front pocket, his expression stubborn. "I'm not forgiving you," he said decidedly. "Cause there's nothing to forgive." He bit the inside of his lower lip and looked a little aside. There was only so long Seamus could handle talking about feelings with this level of sincerity, and his eyes cut back to Dean with a ghost of a smile quirking one corner of his mouth. "Don't think you're getting your cake back, though."