Please don't send hate towards me but , in my opinion, i think Seo-an ( bottom) seems a bit toxic one in their relationship. Like sometimes he's gets too unnecessarily possessive and controlling (this sometimes make the relationship suffocating to live in). I get that he had a traumatic past...but still it's not right for him to treat his lover , whom he says he loves a lot, like that.
All 3 couples' stories were told as if they were the main couple of the story!