Manipulation by being too nice

Can you manipulate somebody by being too nice? Try to research this but I cannot find anything about it. My new roommate is a bit strange and I’ve had people at work tell me that he is manipulative. We are not in a relationship and never will be. But he has a big thing for me will not let my boyfriend come over. He says he doesn’t like anybody in his house. He’s super overly nice and I’m just not sure…