In laws

I really need y'all advice. Okay so I live close to my husband's family as he works from home. So I usually bring my son over and stay for a few days. He is still young. My mother in laws boyfriend always wants to use my car whenever his car is down. I let it happen a few times and now it seems like he expects it every time his car is down. Im not comfortable with it. I want to tell him that but I don't wanna cause drama. Im thinking to stoo going over all together but I want to be fair with my son. What do you suggest????

Update: by close I mean 40 mins with traffic...30 without traffic. And I stay because my baby is young and I guess I like being around to change/feed him etcc. They really just bond with him while I'm there. My son loves company too