Don't know if Im just being a bitch or hormonal or if its justified but my boyfriends step dad is constantly using the…

Don't know if Im just being a bitch or hormonal or if its justified but my boyfriends step dad is constantly using the car we bought. My boyfriend makes the payments and such but he bought the car on my credit. His step dad falls asleep standing up. If he totals that 2017 camry le I swear to everything.... First my retarded sack smokes in the car so this family car we got, we cant even use as such because I don't want my baby in a third hand smoking situation. Even if it didn't smell like a casino, his step dad always has it. Or he is always doing favors for them. So instead of spending the night with me he has to take his step dads kid to a job interview tomorrow. His step dad has a car, but he canceled his insurance and now has expired tags. Im just so annoyed by this shit. Every time he moves in with them they use him for money and now that he has a car, they use him for that. Im honestly pretty done with his family. His mom make a lot of money and his step dad gets disability but somehow their money just disappears? Wtfever