So the last time ex had DS he came out with the gem of 'leave me alone, I'm just going outside for a cigarette'.
I asked if ex smokes around him and he said no (and although he was lying it seemed likely it was just smoking outside within eyesight of DS inside IYSWIM and there's not much I can do about it if he won't admit it).
But within 5 minutes of him being home from this weekend with his dad he picked up a drumstick and said 'I'm just having a cigarette in the car' 
There's not much I can do as ex denies it & you can't stop contact over it (well you can but it's not 'the done thing').
Ex's dad died at 49 from a heart attack (he was skinny and ate well but smoked 40 a day for twenty years) and I'll be gutted if DS picks it up.
AIBU to just feel so frustrated I could scream? 