HP - please be sure of the distinction between alimony (spousal support) and child support.
I'm no lawyer, and I'm not in your state, but I can see that infidelity could prevent alimony/spousal support. The principle is that your W is a responsible adult, she made a choice other than you, and thus you are relieved of responsibility for her.
I haven't ever heard of infidelity affecting child support, though. The principle is that they are your kids, you are responsible for them, you have to support them - bad acting by either parent is irrelevant. (kids don't give up the need to be supported because of the actions of one parent). And then, generally child support is some formula based on the difference of incomes, factored by the percentage of time spent with the custodial parent.
