Did he also try to be closer with the family members. Hyesung found a way to blend by force. When dojun wanted to cut them away, he took matters into his own hands and got accepted. Hyesung is more friendly and outspoken to everyone. Heesoo is like me, we feel left out when didn't even make an attempt to socialise....
i think its only natural. hyesungs an omega but he has superb social skills so he doesnt have any problem interacting with the park family thats purely alpha. betas are basically normal human beings + they cant sense pheromones as much so it makes sense why heesoo doesnt "fit in" because in a biological perspective, hes odd. i dont think the parks mean anything bad about it so hopefully heesoo will grow to feel more welcomed in the future.
i thought they already accepted him and his relationship with dojun :(