What OP doesn't realize is how badly he's messed things up.
First, as everyone has told him, he's not going to be able to get a reduction in CS simply because his new bedwarmer has kids and is unwilling to work. That part is simple. But let's go a bit further.
OP is still married. That means that when his wife gets around to divorcing him, all the money that he's spending on supporting his new lazy bedwarmer and her kids could well be dissipation of marital assets. So not only will he be paying child support, but he may have to reimburse his wife for the money he's squandering now.
Then, to go one step further, we don't have any idea whether alimony might be awarded because OP chose not to give the length of the marriage or the spouse's incomes, but if it's even within the realm of possibility, adultery is listed in FL statutes as being one of the factors which could affect alimony. Admittedly, the courts are struggling with how to reconcile that with 'no fault' divorce, but it's there in the statutes and if the judge is offended enough by his actions, it could be applied.
OP, you need to get your life sorted out NOW. Get the divorce - the longer you delay, the more it's going to cost you in the end. Not to mention that the way you're acting is unfair to your wife and kids.