DH still smokes, I gave up over a decade ago. Every bloody day I'm home with DS he waltzes in, excites the four year old because daddy is home and then expects them to wait 20-30 minutes while he has a leisurely cuppa and smokes in the shed. He often throws in a lengthy man poo for good measure. He, rightly, doesn't want DS to know he smokes which means I don't just have an impatient preschooler to try and distract but an impatient one who thinks he's playing out in the garden with him. I've just slightly lost my rag again and snapped at him so he's acting all wounded.
For context, he has a 15 minute walk from the bus during which he could have a smoke. I have no issue with a five minute toilet break and will happily make him the cuppa if he starts engaging with DS straight away. I do hold a lot of resentment about the division of labour and lack of support during the first year of parenthood which might colour my thinking.