My most recent ex broke down one day in March and told me she was dating her best friend. They'd been moving in on each other for about a month, and finally decided they loved each other enough to start dating. She told me all they did was kiss and cuddle but even if that's true I still consider myself having been cheated on. Even if it was just emotional, the fact that they were both involved and both willing to go behind my back is cheating as far as I'm concerned.