alcoholism is PROGRESSIVE unless halted. Like uncontrolled diabetes. Perhaps the 2 of u can agree on seeing a counselor with experience in alcoholism. The fact is you are not dealing with a fully rational person due to alcohol addiction.
The lies they create are simply part of alcoholism. An alcoholic will lie about anyone, anything, anywhere and according to recovered alc's it becomes automatic.
If it make u feel better let these friends know in a loving way that u feel terrible to see alcoholism destroying the person you love. These people may already realize there is something wrong with his mentation.
When alcoholism began, my wife routinely told her new (drinking friends) that she was single. She told them fabrications to justify her new lifestyle and behavior. Very terrible and amazing things were told to some mutual friends. My aw has since alienated those meaningful friends and is living in a circle with other "drunks".
There is nothing I can do as the alcohol is toxic on the brain and there is no way to reason with an active addict. It is the negative consequences exceeding the perceived pleasure that may motivate them to seek recovery.