Good Morning,
The only person you have to have a relationship with is your boyfriend. I would not put myself in a position to let your boyfriend's family bring you done. Be proud of who you are and do not stoop to the level of his family by being rude and not nice.
I would stop apologizing to his family. I think they could be more respectful of you but remember you cannot change others only yourself so don't react to their pettiness.
Kindly,
Kitt