This is clear grounds to not continue the interaction. Look, the guy likes to drink. You’re not going to be able to keep him from drinking. There’s a possibility that he’ll drink even more when he’s in a stable relationship and not less.
You can ask him to not drink around you. That might be a compromise that will allow you to continue dating. But it’s probable that you will be perceived as asking him to change himself for you, and nobody wants to change themselves for a partner.
Waiting four dates to show you his drunk side could mean he’s good at controlling his drinking, it could also mean he’s an alcoholic.
I like to drink. Not all the time and I’d happily give it up for a healthy, working relationship. I consider alcohol to be a tool and not a crutch. It helps me get through certain situations and gives me new ways to approach problems. I walk to the bar when I drink outside the house.
My father was an alcoholic and it took me until well into my twenties before I could trust myself to let alcohol fully into my life, that I could control it.
Most people are not me. Alcohol for them is a crutch they use to prop up their self-esteem. If you ask him to not drink around you, be prepared for a negative reaction, then silently stop returning his calls.
You don’t need an alcoholic in your life.