Perfectly put, Forinil! And for those who would argue, note that it reads, "everyone is fully informed and consents". This means it is only cheating is one of the people involved is either not informed or does not consent. This works for many more people than one might expect and is a valid lifestyle.

Her ex dumped her for something that happened who knows how long ago, before he even knew her. He's the dumbass here.

You're a fucking idiot. not every 12 year old is the same, and I'm sure you weren't the perfect little saint at 12.

I completely disagree. To assume that all 12-year-olds have the same experience is very close-minded. At that age, it is really up to the caretakers and people in their residence that define what they are exposed to. A kid that age who is homeschooled, isn't allowed to watch "popular" media, and has a similar group of friends, is an example of a kid who may not be aware of conventional relationship norms in early puberty (I know, I was one). There may also have been blurred lines - for instance, what she later decided was cheating may at the time have seemed to be dating two people - which a lot of people would not consider cheating until an exclusive relationship is agreed upon. 12-year-olds are dumb. They don't fully understand romantic relationships at all. I thought it was a good idea to prank my introverted boyfriend by telling him I broke up with him for an entire day and writing him a letter that I liked another guy in the class. Yeah, it didn't take me long to figure out that was a ridiculously stupid idea and learn more about relationships, but mistakes can occur at that age simply from ignorance. It shouldn't have an effect on relationships as an adult unless it was explicitly done to intentionally hurt someone. Even then, sometimes that's something one will grow out of.