Ways to catch out DH

[Appymummy]

I think my DH is smoking cigarettes and possibly weed. I need to try and catch him any ideas to do so? I have had my suspicion before about smoking cigarettes and asked him outright a few times and hes denied it and blamed his log burning fire at work!
My reasons for this:
I can smell smoke on him
He sometimes brushing his teeth at random times
He sometimes chews gum
I sometimes smell weed and he tells me I am mad and it's probably the flowers!??!!
He has had terrible mood swings but puts they down to stress of work, new baby and house build
He snacks ALOT at night.
He used to smoke both in his 20's.
Thoughts??

Weed smells pretty differently to flowers

I'd ask him out right!

What do you mean 'catch him'? Only you know how/when/where he is likely to be smoking

Why would he have a log burner lit at work at this time of year? Mine hasn't been lit for months

What happens if and when you catch him out? Divorce? Separation?

Bizarre.

So what if he is?

What a strange plan.

I want to know the truth instead of being lied to. He is very up and down with his moods and this is something I want to address. He always denies it when I ask do need to find out by catching him out. No need for divorce just honesty, but I hate smoking and if he wishes to do so then that's his choice just don't want the secret. If he can be secretive about this - what else is he doing?