[Erasing all thought and taste of Ticky or Tikki or whomever that was is a very good motivator. And when he takes the opportunity to explore deeper in Walker's mouth it really shouldn't be a surprise. After all, he is an inspector and he is very good at his job.
Maybe there are a few things Link hasn't said because he hasn't found the words to say them or because the words aren't exactly authorized by a higher entity in the order, but in this way it feels like he can express some of the trust and protectiveness he has grown to feel for the exorcist he's been sent to watch over.
It may also be seen as practical that he continues to kiss since there has been no release of confetti as of yet and he is aware of the bots sometimes demanding more kissing. Certainly one kiss is better than two.