He kind of can't believe this is actually happening. He'd realized that Sonic wasn't really interested in that sort of thing months ago and had gotten himself to realize that there were more important things than giving in to growing physical urges. Which has left him rather completely at Sonic's mercy, here and now, as he's completely derailed by the taller hedgehog actually being interested.
He bites his bottom lip a little bit, hands curled a little tighter around Sonic's arms, as those teeth tease down and his shirt gets tugged aside so they can keep going. He makes a soft, shaky little sound at it, but it's a pleased one, all the same, something that sounds a little nervous but warm~
"... ah... mnh..."
Flexes his fingers a little against fawn, obviously not really sure what to do with himself, other than let Sonic help himself to his throat and shoulders.