People keep asking this. It's likely OP DID tell his mother they were his father's cigarettes, but she believed her husband over her son because he's the adult and OP is the child. My grandma used to live with me, my siblings, and my parents when I was growing up. She often lied to my parents about us to get us in trouble. We would try to argue but my parents would always believe her because she was the grownup. Then one day they caught her in a lie and then the game was up. She got caught in a few more lies, and then she was soon put in a retirement home.

I never understood why parents wouldn't believe their own children, unless they had a prior reputation for lying.

But why wouldn't you believe your own mother, or in the case of OP, your own husband? Adults find other adults more credible than children by nature. That's just the way it is. I don't blame my parents for what my siblings and I went through as children. They just acted on what was most plausible to them at the time. I blame my liar of a grandmother.

What Op needs to do is get some sort of proof, go to the doctors, get the father caught in a lie.

The previous poster is correct. adults tend to believe adults. Usually because they believe an adult is less likely to lie than a child would to get it off trouble. But more times than not is because they are in denial and the WANT to believe the adult. This is why we end up with children being sexuality abused fit years by the same person. They try to tell then they are called a liar and punished for telling. You can usually smell a smoker. Their clothes, breath and even sweat. OP'S mom seems to be in denial.

Does it really seem to you that his mother would blame his dad? He'd just get more therapy for the weed.