Having been married for going on 27 years, from your posts so far it seems to be more involved than just smoking an occasional cigar.
Women, not all but a large percentage of them, have a nasty habit of stewing on problems for a long time. They get pissy about all kinds of other trivial things while avoiding the one that really bothers them. You need to make sure that there's nothing else brewing under the surface.

Another thing, NEVER let the "intimacy" thing lapse. Even if it's usually her that causes the time conflicts, she'll blame you for the lack.

When our kids were young, my wife and I both had VERY busy schedules. I went to college full time and picked up any odd jobs I could in any free time, and my wife worked 2 full time jobs. It really played havoc on our marriage for a few years. Fortunately we were able to remain stubborn enough to work through all the crap.