Asalamalikum …my husband married to another women in my absense (I was in USA) when I found out and ask he said it was just given her a last name cause she is orphanage. But her family is alive. We came to USA and I caught him kissing a women and he was drunk.
A legitimate ground for divorce is due to behavior contrary to Islamic norms. If one of the spouses is found in adultery or fornication or drunk this is a ground for separation.