OK, Mirch bhai, what you need to do at this point is so take some Tums, and actually have a heart to heart conversation with him. Tell him that while you enjoy his company and his family is welcome to your home anythime, it is obviously creating misunderstandings with his wife. His homelife is more important and he needs to focus on that first. Maybe his wife is getting insecure about where his time is being spent. (some women sometimes get insecure over little issues :o). So maybe all she wants is reassurance that her family is priority and not yours!
Do it, otherwise it could get more complicated.
If he really takes you as a big brother, he will definitely understand your point of view.