One of the worst things in the world is when you meet someone of the opposite sex who other than the fact they and possibly you are in a committed relationship you would otherwise be extremely attracted to, then you have months of thinking about who they are dating. In your mind this person is an absolute loser and under other circumstances (you were not with the perfect person you are with, and they were not with the D-bag they are with) you would be the perfect couple. But then comes the day and you meet him and they are absolutely cool and probably better for this person, and maybe the person you are with, than you ever would or could be. That is awful.