Trying to avoid secondhand smoke?

its not as easy as "tell them to smoke outside." i live with my mom and stepdad, rent free. i quit smoking about 6 months ago, and my step dad smokes like a chimney. its disgusting because he does it right in the kitchen and always blows it in my face. i know i dont really have a "right" to ask him to smoke elsewhere because its his house and like i said im living here rent free, but its extremely frustrating knowing that im still getting his secondhand smoke and i am still at a risk to get diseases that shouldnt be a worry for me since i quit myself. do you have any advice on what to do for this situation? it just gets worse every day and i can't stand the smoke.