The kiss was actually better than I remember? Like, don't get me wrong, it's very much a dead fish kiss, but despite that the actors still give me the feeling that they want each other. Perhaps that's what's so frustrating. The sense that these two could have giving us a blisteringly hot kiss, if only they'd been allowed.
I'm trying to recall Ocean Likes Me; I think Han Gi Chan had good kissing in that? I haven't seen Jang Eui Soo's other BL(s) to compare.