It looks like the author's story is always shown in pink font, so when Geonju thinks that Seom is adorable, then maybe it's only the author's and not his own thoughts? Because it's a bit weird to have a flashback about Heewun at that moment. So maybe he actually has feelings for Heewun but are forced to go this route with Seom because of the author. It'd be interesting to see him becoming self-aware later on, but I totally ship Heewun with Wuyeol >.<
I'm just here for the comments XD
I guess posting spoilers actually help support the author because everyone's trying to find out what's going on. (me included)
All I can say is, Seungho better not still be in denial next ch