I am five months pregnant. My partner and are both very happy about it. We have been together for several years and consider ourselves a stable couple. There is only one serious source of conflict right now: I gave up smoking a year ago when we decided to start trying to have a kid, and he still smokes. Lately the second-hand smoke has been making me sick to my stomach. He always goes out on the balcony when I ask him, unless it is raining or something. But he never just does it on his own. He does not have any plans to quit smoking, and I am worried about the baby. What should I do?