Heheh, thanks for the compliments... and the kiss is in ... er, either volume 18 or 19, at pretty much the tail end of the "kami no kijutsu" arc, frequently referred to as the "card arc".

(I only just got my own copies of 17 and 18 a week ago in Japanese, and haven't had time to look all the way through 17, so I'm not sure how far that story arc goes... and we should get it translated here in about two years. -_-)