Answer:
To sell alcohol is a sin. To associate with a sinful person is incorrect as that indicates complacency to the sin. However, if one is able to influence the person on the right path and stop him from the sin, then he should do so.
If it is possible to advise the wife against alcohol so that she in turn may advise her husband, then she should do so.
And Allah Taãla Knows Best.
Was salaam
Mufti Ebrahim Desai