I honestly think you can predict it if you always communicate with your partner. If communication breaks down often, there's things you can't talk about, or they're frequently the cause of your unhappiness, then that's pretty much a sign the relationship is doomed at some point. If you communicate properly, and you help each other grow into a person you'll always love, then the relationship should last as long as it's built upon a strong foundation (similar passions, same long-term life goals, etc..). The way to achieve this is really simple - you train your partner and you let them train you, by encouraging them to do things you like, not by waiting until they do something wrong then punishing them/getting angry. It's my belief that if a relationship breaks down it's because it was either not build on a strong foundation or the two people involved didn't put in the work it takes to build a strong relationship. But then again to do all that takes a certain kind of person that makes up a pretty small amount of overall people, which is why I would never seriously date the vast majority of women, really.
And yes, I should have said "single parents", but as we all know with the way the law works it's much more common to find a single mother than a single father, and since we're both (I assume) straight men it makes more sense to talk about single mothers anyway.
All that being said, I'm not trying to talk you out of this relationship. I'm just trying to pass on my knowledge about human relationship to help you (or anyone reading this) to make the right decisions for their life and not do anything blindly and regret it later. If you can find happiness, responsibility, and a supportive relationship by dating a single mother, then by all means go for it.
