Seme's dad wanted an heir but seme wasn’t interested in getting into a relationship or marrying whatever but agreed to provide his father with his sperm so that he can use it along with an egg donor and surrogate. Uke happened to be that omega as he was already working at the host club (probably got noticed by the gang members and was offered a large sum of money to be that surrogate). Due to security concern he was ordered to live where seme was living. At first seme got annoyed to see him or ignored him altogether and uke was scared of him. But they gradually got to know each other and fell in love. They didn’t have s*x until in the latter chapters.
Thank you for the better translations! I'm still wondering how he ended up pregnant. I mean, he said he's a surrogate, but they really didn't go into detail and say if he it was artificial insemination or if they had a round of sex while he was a host. Considering he said they haven't sletp together, im guessing it's the former. But! I wonder why Beom decided to go that route or that he needed/wanted a child....Anyway! They're super adorbs.