There's a tiny squeak when instead of being pushed away, she's being pulled in. The kiss has all the other words she may have said fade away until she's clinging to him just as hard as he is in return.

"You certainly won't ever be perfect if you keep saying 'one of'!" She scolds with a watery voice, her expression just shy of a pout. "You're the only one I've ever wanted, A-Cheng. I've loved you since you were being so stupid at Gusu, smiling like a fool every time you saw me."