It is non-con, he also drugged him. It's expected. Ceaser has been this insane since the very beginning and constantly throughout. He doesn't know how to express love, upset and jealousy normally because he's not a normal person. Someone who has been living life in survival mode since childhood. I'm not saying this to excuse his behaviour, it's not reasonable or justified, but we knew he is this type of psycho from the start and his abusive nature has never wavered or lessened throughout the story or gone through a development
https://pawmanga.com/manga/roses-and-champagne/
This is the ones I read but it is translated but idk if I'd consider it raws.
Since I couldn't wait, I checked the raws and maaaan, I so wish I could read Korean. Leewon got bombed! Though he only injured his hands it's still pretty intense. There maybe another hired killer other than that sniper. From what I understood the sniper doesn't use bombs. Leewon will have a lot of screen time with the Lomonosov group's successor after the bombing.
There will be a couple of chapters without Cesar and then BAM! They fight and it ended with Cesar assaulting our seductive lawyer, again. For hours. Though I am fine with such scenes and will continue to read this, it's still saddening as I thought they are way past such acts. Of course, Leewon forgave him the morning after. I am sure there will be a lot who aren't okay with this.
Again, I can't read Korean, this is just how I understood the raws. I can say it's pretty clear though that it was a non-con scene based on Leewon's reactions and expressions.
#-.-)