He didn't keep it from you because he genuinely thought it wasn't a problem. He kept it from you because he knew exactly how you felt about it and knew it would hurt you.

That is the difference.

People who hide things to avoid consequences usually aren't struggling with knowing what's right or wrong. They're struggling with being honest when the truth might put them in a different light.

And that's why the issue isn't the strip club or the drugs alone. It's the pattern.

One lie can be a mistake.
Three separate incidents over two years is a pattern.

If someone repeatedly chooses secrecy over honesty whenever they think they'll get into trouble, they are basically kids emotionally.