But, the last person I met was more attractive in photos, and she was one of the best girlfriends I've ever had. And besides, she was still pretty.
I'm not sure if you would fall out of love though, being in love is a bit extreme so I don't know if visual difference (and it likely wouldn't be a huge difference) would be enough to stop the way you feel.
If someone is heart broken over a photo then they probably didn't care too much about the person anyhow. They would have just been really horny. That seems like a waste of an adventure and experience, doesn't it? Don't get me wrong, I get it, I've had it happen. But I dunno, I can't rap my ahead around this one.
I just want to add, you can absolutely fall in love with someone over the internet. Nearly three years ago I started falling for a girl over the internet, never having met her. I've only hung out with her twice, one was a seemingly impossible random happening that lead us to being in the same place at the same time, which is strange considering we both lived in different towns and neither of us lived in that one.
A few months ago, I thought I finally got over her. As of the last few nights, I found out I'm wrong. Nothing can be done about it, but that's okay. The point is, it can and does happen.