Family Disagreements with Parenting

I don't have any children (yet), but for the time being my boyfriend and I live with his parents. His little, two-year-old nephew comes over once a week for a visit. My boyfriend's parents smoke a lot of weed and don't stop when the baby is here so he's always inhaling the smoke. And just now, my boyfriend's mom has the oven on "clean" (so the whole house is filled with smoke) and just has the baby inside the smoky house. Our room is sort of detached from the rest of the house, so I offered to take the kid with me and the dogs so there would be fresh air, but she said he's fine. He often has a cough and like, recurring throat (I think) infections. This just doesn't seem right and it bothers me so much, but I'm terrified of my boyfriend's parents so I would never, like, try to tell them how to parent their grandchild or anything. But would you do this with your child?