It's a little different in NY as far as support goes.
Child support and spousal support are different. There is no set formula for spousal support other than the ages of both spouses, the amount of time they have been married, the health of both spouses and the ages and number of children. There is no numerical formula to follow.
IMO the best defense Future could use is the support he paid her was under the notion that it was a "controlled separation" agreed upon by both spouses in order to work on the marriage. Since his W has continued to conduct her affair and not take any active steps to work on the marriage any further support will be determined via an AGREEMENT (formal). It will cover your ass Future and there really isn't a defense your W can use to counter it.
The nature of the support has changed due to situational change. That is how I would present it to the attny you retain.
