My FIL smokes, like a chimney and in his own house. He's getting over a very painful operation and so is smoking more to cope with the stress/pain/sleeplessness - often through the night. MIL 'let's' him as it's 'his house', she's old fashioned and claims to be sick of the rows. I don't think FIL will ever give up.
It's so smoky in the house that our clothes, hair and luggage smell for days afterwards and we can't stay more than a night. Everyone in the family who visits feels the same so they don't have visitors stay for long. MIL often airs her regret that visitors should stay longer and I honestly don't think she realises the extent of the issue, having lived with it for 50 odd years.
AIBU in the not-so subtle hints to drop - leaving windows open, constantly closing doors and taking DD (toddler) outside to play at every oppportinity?