Xie Lian would probably be the first to catch feelings, but Hua Cheng would be the first to bring it up to him (before either of them say a thing to Shang Qinghua).
Think I like the angle of new/old (in the sense where to him it's new, but to those who can feel it he feels very, very old). All the more reason to enforce cuddles. And being nice to Xie Lian and really not caring about him marrying a ghost is always going to win points from Hua Cheng.