@I_love_older_women Tbf, by the way Bong Won acts like, it seems like he is way older than the others. I think it was mentioned in one of the last two chapters before this one that it doesn't seem like lots of the vampires know how to "socialize" like normal (present day) humans do, and most of they do is imitating what they see from other media. Him declaring he wants to have a relationship with Yi Gyung is what I assume he might have seen in older movies, like, who does that nonchalantly, nowadays, lol?
Perhaps Ho Seon thinks he is trolling, too. Yi Gyung is "special" to him to a degree, even though I don't think it's "romantic", and well, she is the one that came to *their* world unstabilizing everything and everyone (him included).