Silon has never cared about his body and has always used it as a means to an end. So, that sorta checks out. Its not like he was in a relationship with Jun and he planned to never see Jun again. In fact, hes been in love with Jin for years and after her death he was fucking and all that. Even during sex with Enzo 2 chapters ago Silon wasnt fully there or into it. He was just using him as an escape. Thats kind of his playbook and fits with his character. It would've been nice if he hadnt slept with Enzo but its still in character. I personally dont like how Silon never really groveled like that. It was always Jun having to cross that boundary between them.
im sorry but "not in a relationship with jun" is such a weak excuse when we've come this far in the story really. even in the beginning of season 2 where the author decided to blast the readers with explicit sex scenes between silon and enzo, it gave off the vibe of ntr with how jun was in that mansion with them and its worse knowing that silon was well aware about how jun felt about him all this while.

what an ass ending bruh its so ridiculous jun was just there to fulfill the author's ntr fantasy