Seth blinks in confusion at Daniel's snort and subsequent descent into unintelligible noises. He might've noticed the whipped cream himself if he weren't thoroughly distracted Daniel's laughter.

"What? What are you..." he trails off, smiling in confusion. If he weren't cheery himself, he might've been starting to feel offended at Daniel laughing at him, but as it is it's only contagious. He only barely manages not to pull back when Daniel reaches out to poke his nose, which only furthers his confusion until it's finally cleared up.

"...Oh," he answers, then, "How was that that funny?" Though he's laughing a fair bit himself, even if that's mainly at Daniel's amusement.