Haha, love... a bigger lie than religion.

The only reason romantic love exists is to cloud your judgment long enough to get you to fall into the trap. Once you're stuck with a family and much of your life sucks, you can still get out but at a high cost. The real purpose of marriage is to raise that cost. Kids are generally better off with two biological parents caring for them. Hence, you're likely to bite the bullet and soldier on as long as you have to.

Some people will tell you that you need to do what's best for number one and be a proper example for your kids lest they get stuck in sub-optimal situations when they grow up and find someone better.

Grass isn't greener on the other side. Other humans are unreliable as sources of happiness for us. That's the way it is. They disappoint us in various ways or they abandon us either by dying or by leaving us. They've got an agenda of their own. We're dependent on other people for essential things such as survival and the continuation of the species. But that doesn't mean getting with that program is always best for us as individuals. The lucky ones are the people who have the temperament and constitution to derive their meaning and happiness from sources other than other humans.