well there are many people who have been in similar situations, whether bdsm related or not. There's never a 'right' answer for this sort of thing because whatever you choose to do, someone will be hurt, whether it's you, your spouse, your kids, who you want to be with etc. etc.

We can't tell you what to do, it's something you have to figure out on your own. It's a sticky situation and no one here wants to be the catalyst if everything goes awol because you took their 'advice'.

Play the 'what if' game... because no decisions have been reached yet, it's best to do that now. What if you left your current spouse? Would your other also leave his spouse? What sorts of complication would arise with your kids? How they take it will depend on their ages etc. etc. there's a lot to think about and making sure you think of the possibilities beforehand.