Lose your kids in what way?
They can't fight for access and choose to very active in their kids lives?
So I guess you don't know anything about divorce.
#1. It's very difficult and very costly, both financially and emotionally, and causes lots of problems for very young kids (age 6-12).
#2. The kids will be split spending a set amount of time with each parent separately. This alone is enough to not get a divorce for lots of parents - if they both love their kids why would they want to only spend 2 or 3 days a week with them instead of every day?
#3. This is partially covered by #1, but again the financial part of it is huge. Not only the money spent getting through the divorce, but they no longer have a joint income and the husband or wife has to relocate. Between all of that and having to see your kids for half the time, it's no surprise
at all why couples who don't have sex anymore cheat. There's plenty of other smaller and more context specific reasons I'm not listing here, too.