This is just my opinion, so don't get offended while reading this.
Love isn't real. The only point of any life is to survive long enough to reproduce, and then make sure your offspring lives long enough to reproduce. Of course humans want to be more than just sex machines. But notice how unlike gathering food and reproducing, you don't see love in any other animal. Since we're evolved enough to have emotions, we made one up to make our relationships more interesting, because of how long they were. If you want your offspring to survive, you obviously want to give it the most protection possible, so splitting up before your offspring is old enough to reproduce is a bad idea.