ANSWER:
If he requires you to mix with any of his male cousins, this is not permissible whatsoever as they are non mahram to you. You must not come in front of them nor mix with them. You have to hold your grounds, be diplomatic with your husband but not compromise your Islam.
If he wants you to entertain females only, then you should show him compassion by honoring his guests as this would increase the love between you.