Moving in with family is changing my relationship

So my boyfriend and I moved into his dad's house this week. I am so appreciative that he's letting us stay but my boyfriend is so different around him. He and I are super affectionate to each other still but when his dad or stepmom is around he doesn't even acknowledge me. Not touching because I understand that but like even looking or talking to me. And he has had an attitude with me whenever his dad is around or he gets a angry tone he doesn't yell but he gets the tone. I don't know what to do about it because I don't want to sound unappreciative or anything.