Seth doesn't realise just how tense and tightly wound he was until their mouths finally connect, and Daniel is kissing back, Daniel is most definitely kissing back and Seth can just feel all the worry and the tension drain out from his shoulders and his neck, especially his neck because Daniel has just put his hand there.

He rests his own free hand on Daniel's chest, and he's so excited he has to make himself take it slow, to take his time and enjoy it, because he can actually tell Daniel is inexperienced and unsure about this, and Seth doesn't want to overwhelm him, Seth wants to make sure he is along for the ride. And Daniel definitely is, he seems to be, because he may fumble a bit but it's sincere, it's so obvious now that they're both enjoying it, and Seth is so relieved and so excited.

And Seth was right, Daniel's lips are very soft, like they were made to be kissed, and how on earth could Daniel be inexperienced, why hasn't anyone else taken the chance to do this. He pulls apart just a little bit, having to remind himself to breathe, and he realises he's smiling, and he opens his eyes a little as he leans his forehead against Daniel's for a moment, making his glasses askew because they haven't gotten far enough to take them off, and Seth reaches up behind Daniel's head to weave his fingers lightly into his damp hair.