How do you think it's going to look if you refuse to let the cops into your house? It's going to look like you have something to hide.

No, there is nothing wrong with having a beer or two a night. But if your husband is concerned about it, he should look here:http://www.niaaa.nih.gov/alcohol-hea...binge-drinking
Just to give him an idea of what is an appropriate amount of alcohol and what is not. Generally, four beers in one day is pushing it. Many psychologists consider 14 drinks or more a week to be a sign of alcoholism.

Since there was no blood alcohol test, it is your word against the cop's word as to the intoxication state of your husband that night.