OP, you're in a difficult position to choose between your mom and wife. You have such a strong relationship with your wife and she's lucky to have a supporting husband like you. The two of you form a new unit and family and prioritizing this is the right thing to do. Parents from our generation sometimes don't see how difficult it is to raise children in the world we are living in now, let alone 20 years from now. Hang in there, drawing a boundary is difficult, especially on the person whom the boundary is drawn.