(1) A court in which any order under this Act has been made may, on the application of the married woman or of her husband, and upon cause being shown upon fresh evidence to the satisfaction of the court, at any time alter, vary or discharge any such order, and may upon any such application increase or diminish the amount of any weekly payment ordered to be made, so that the same do not in any case exceed the weekly sum of $100. If any married woman upon whose application an order shall have been made under this Act shall commit an act of adultery, such order shall upon proof thereof be discharged.