How do I deal with disliking my boyfriend's best friend's wife? She is a monster.?

Ive been with my boyfriend for 2 and a half years, and his best friend is amazing, the three of us have a great time together. His wife however is another story, she segregates herself often, makes her husband cancel plans with my boyfriend, she wont talk when i attempt to chit chat, the list goes on and on. Recently shes been very catty towards me, even getting so y to tell me that I shouldnt wear a skirt, I get the vibe she thinks Im into her husband. How do I make this relationship more bareable?