Well, for me personally, drugs are a deal breaker. Now, I’m not perfect, so I’m not being all judge-y! I have minor children, and I have already seen first hand death, addiction, prison records and ruined lives among their peers. And to be (I’m assuming) in your twenties and people continue with that nonsense? It’s just not worth it!
And the lying? It doesn’t matter what the person is lying about, where is the bond if that trust is broken?
Deep down when people know you are right, their defenses come out and try to turn it around to look like you’re the one with a problem.
I think he MAY change, eventually, but you are not the one to make him do the right thing or wait around until he grows up. You CAN leave. Then maybe revisit the situation with a fresh perspective in the future.
Though I run this site, it is not mine. It's ours. It's not about me. It's about us. Your stories and your wisdom are just as meaningful as mine. 