Sometimes people not telling their family that you are dating them isn’t out of disrespect or shame, but rather out of fear of the response. In a lot of queer relationships, introducing a partner as a friend can be commonplace for safety purposes if the family isn’t accepting. Even if it isn’t a queer relationship, sometimes families can be overprotective of their kin or aggressive towards the partners, so there’s a chance your bf is protecting you. It might be good to talk to your bf about it