I remember reading this bl manhwa and I forgot the title..it was like an arrange marriage ...

I remember reading this bl manhwa and I forgot the title..it was like an arrange marriage between the families and there were twins dominant omega and a recessive omega..and then the dominant omega was suppose to be the fiance but he runaway with the recessive omega's (ex) boyfriend..and now the recessive omega is taking the role of his twin brother as the fiance of the alpha...and also the alpha was said to be "sick" but he just have a unique type of traits I think..