Hi areenhaque
Welcome to PC!!!
I'd say that you need to find a good time (when there are no stresses or strains) to tell your husband the
true importance of the issue for you.
I may be wrong, but reading between the lines with this:
I'm not bothered about him smoking as much as I'm bothered about him not keeping his word. He keeps telling me that he won't do it but he keeps doing it.
You're perhaps feeling a general lack of trust in him from this, with him saying one thing and doing something else without your knowledge, maybe you feel betrayed by him doing that, maybe you feel he's disrespecting you or not showing you respect by "casually" telling you something and then.........??
Maybe for him that's
way off the truth as he sees it, just different perspectives, but your feelings do matter

And the discussion with him doesn't even necessarily have to be confrontational maybe reiterate with him that
it's fine that he's smoking, and you recognise it's not even regularly anyway..........it's just that when he tells you...........it makes you feel......because...........and you'd really like him to............Maybe he will "shrug off" some stuff...........different perspectives..........and you can even acknowledge that to him/perhaps even understand or show understanding that things like that aren't as important to him..........but it's about helping him acknowledge/understand your feelings as well.................
And maybe you two can even reach a compromise...........as in you accept that he may not remember to tell you every time but he will try to tell you when...........Just some thoughts.........

Alison