Need help looking for BL

Hiiii, I need help looking for a BL. It's a omegaverse, not sure if it's a manhwa or manhua. I don't even know if it would be on here but I want to try lol

From what I remember of the plot, it's about a recessive omega that has to take his twin's place in marrying an alpha after he runs away. The alpha has issues and is separated from the family's house in an annex. I remember the title being in a different language, I want to assume French? The omega has black hair and the alpha is blonde. I can only describe the art style to be very unique. Like not real life like but I guess close? It was still ongoing from the last time I read it. I had found it on Qtoon ( ´ー`)

If i need to add more info I'll try my best to remember!! I just randomly remembered and I wanted to see if I could find it to continue reading. Thank you!! (⌒▽⌒)