This happened to me. My girlfriend I had known since I was a little child and was VERY close to and madly in love with, fell in love with someone online and it destroyed our relationship. I was devastated and still am.
She gave her heart and thoughts to another person and I feel so broken. This person broke up with her a few weeks after she broke up with me, and all she ever does is cry about how broken heart she is over THEM, not me. She only knew this person for like 6 weeks! Can you believe it? She had known and loved me for many years, but just threw it all away over this person on the internet. I'm heartbroken and I just cant understand it.