Kohki
"The person I loved fell in love with someone else." It feels as though a part of your soul was ripped from you, and it leaves an incredibly large void in your person. Love goes far past sexual gratification. Sure, I'd get pissed if I was cheated on by a guy that skeets on my girlfriend, but I'd just be pissed and only somewhat hurt. If they fall in love with someone else, however, that means that they lost more than just their physical attraction towards you. It means thay no longer have the same mental and emotional attraction they had for you before. Not only that, but it's more permanent an empty void than being cheated on leaves.
I whole-heartedly agree.
...If someone cheats, is unfaithful, they can be forgiven. And you can move on.
But if someone falls in love with someone else, there's nothing to forgive, nothing you can do. It's not even their fault. People can control their urges, but actual love, is unstoppable.
...But, that doesn't really answer the question.
So, I guess, i'd be more angry if someone cheated on me. And if they fell in love, the reaction would be more like, hurt, as opposed anger. Because there's nothing that can be done about that.