This requires negociation. First - if you have not already made it clear - you must tell him that you don't like the smell, and ask him if he would mind smoking in his own room at least some of the time. Open the windows when he lights up in the drawing room, or if it is too cold, light a Berger Lamp (amazingly efficient) or anti-tobacco candles. However, you must both show tolerance and go half-way. If you make him feel like an outcast, you will get nowhere. Most smokers are more than willing to make an effort.