Of course, some people can only screw up their courage to leave an unhappy relationship by hopping, like anxious frogs, onto the next lily pad. And some people engineer spectacularly hurtful breakups because they enjoy creating drama, or they need to force the other person to leave them. And sometimes they just can't help falling in love with someone else, or they're in the process of becoming someone different than the person who once swore, in all sincerity, to be loving and true 'til death dost them part.
I've been cheated on more than once, and nothing is more wretched. I've howled at the moon and torn my hair over the unfairness of it. Years later, I could start to acknowledge the role I had played in these dysfunctional relationships, and it was both humbling and healing. And now, many years later, I am mostly grateful, because the breakups that ensued pushed me on down the path of my own personal journey. And I must say, I am happy where I've wound up, so I guess it was all worth it...
When it comes to matters of the heart (or loins) I can only say this:
The older I get, the less judgmental I can be. Life is complicated and messy, and nobody knows what goes on behind closed doors. [cue Charlie Rich]