Until you have gone to a personnel office with the finalized divorce decree you are to support your spouse with the 'With Dependents' pay that the Military member is getting. If there are children involved well that's when personnel and the courts get involved even more.
If the spouse has any clue about what is going on they can report the active duty person to their command and get the service member in some serious trouble.
Point is: Until divorce decree is issued and divorce is finalized (i.e. alimony, child support, etc) the dependent pay is there to be issued to sustain the dependents even if they are to be divorced soon.
Seen this way too many times guys and gals getting NJP'd because they were not supporting their soon-to-be ex spouses and the spouses ratted on them and they had to by commanding officers orders support their soon-to-be ex-spouses.