Living with a Gemini..?

Well I am a Sagittarius and me and my hubby (which is a Pisces) live with another married couple a Pisces and a Gemini... And my husband is best friends with the Gemini. But I cannot stand him for the life of me, I dunno if it is because we are complete opposites or what. But he can be very rude and super negative and bitchy. Its like all he does is complain. And it irks my nerves. Can someone please tell me a little more about Geminis and why we may clash so much??