I don't think you're wrong about being upset at all. Drugs are something you don't want near a child, during or even after pregnancy.
But being that I'm only 17,
I don’t know what other advice to give other than to sit him down and have a nice calm talk. You need to make him understand that its not good for his child to grow up watching a father doings drugs; it’s not something that’s healthy. Now that he's a father he needs to understand his priorities, one being that he must do what’s right for his child.
So, if he wont quit he has to do it else where, out and away from his kid.
Or maybe he might even want to seek some help, since I don’t know… if you’re willing to go so far as to sneak out in the middle of the night just for a smoke you might have a bit of an addiction?
Some information you might wanna know:
"Regular use of pot can lead to a host of serious physical and psychological problems, from panic attacks and impaired judgment to delayed puberty and lung cancer.
Marijuana contains 150 different elements, including THC. When marijuana is smoked, THC flows through the bloodstream and interacts with different areas of the brain, such as the hippocampus, which is responsible for memory, and the cerebellum, which controls movement. The highest concentration of THC, however, binds with the middle of the brain. It is this binding that triggers the secretion of the feel-good hormone dopamine. This is what produces a feeling of mellowness or carefree numbness — a "high."
Because marijuana affects the hippocampus, the part of your brain that forms new memories, smoking it can inhibit new memory formation. That can be a serious problem if you're in school, trying to learn. **There have been no studies on the long-term effects of marijuana on child and adolescent brains, so the extent to which smoking pot permanently damages brain cells is unknown.**"