WOW. Husbands best friend.

My husband just told me that his business partner (and best friend) hates me and calls a whore. Keep in mind I have never ever cheated on my husband and treat him like a fucking king. His friend is short and fat and jealous. I also treat him amazingly and cook for him constantly and have tried to hook him up with friends of mine before. I am feeling beyond heartbroken and betrayed. I honestly want to leave my husband over this. How could he be so close with someone that talks shit about me?????