
I appreciate how this manhwa doesn't shy away from showing raw, messy emotions on both the FL and ML. Their unhinged, cringey moments actually make them feel more human that's refreshing. Now for the rant! He knew it was her and still acted like that? Why is he behaving like she wronged him when he's the one who left without so much as a word? And now he's bitter because she has a kid without even confirming if the child is hers? Seriously? And what’s up with the engagement? If his political position is so damn powerful, then why is he suddenly tied down like that? Bitchass boy is seriously pissing me off.

I wouldn't say he left without a word. Technically, MC freed him and explicitly asked him to run away before bowl cut executed him, so she wouldn't have been all that surprised about him disappearing. She probably fled not soon after considering she was still within betrothal distance of bowl cut.
I doubt he's unaware that the kid isn't hers - that probably doesn't stop him from being jelly that she's raising a kid that _isn't his_. He's mostly bitter cuz he couldn't find her for 3 years and whatever fantasy he built up in his head over that time wasn't instantly reality when she saw him.
Also, pretty sure the silver dude he met in town implied his country was in a mess when he begged him to come back (i.e, back when bro was like 'fu, u made your bed so take a nap - not my problem your country sucks without me'). Wouldn't be surprised if his position wasn't all that secure when he came back. I mean, he did disappear for the better part of a decade (I think?). The only reason he'd have any support at all is that his step bro is on his side (I think?). Also his cray-cray search for FL (i.e, f-ing off to attend social gatherings in another country immediately after taking power - wtf?) probably didn't earn him any brownie points with his court, so I wouldn't be surprised if he had to make some concessions to stay in power. In his flashback monologue, he mostly wanted to find MC to 'watch over her from a distance' if she'd already found someone else (haha, lies) - so I think he's not beyond making up whatever rationalization he needs to suit his sort-of infidelity (mf prolly might make up some weakass excuse about how 'his heart was always with MC' or something.).
I'm more concerned with the mental wellbeing of the fiance. I know he's a duke and all but girl - are you srsly getting engaged to a dude who gets drunk all the time, spends most of his time looking for some random girl and literally _mopes over a portrait of her every night_? To the point where his behavior is well known enough for gossip of it to trickle down to the slums?? Girl, where is your self respect??
Awwwwwww