"It was just out of the blue," said one Houston husband.
A Facebook romance that he says caused his wife to leave him and their kids.
"I don't know if it was a friend of a friend and how it really happened. I started noticing her online, on her phone, late at night and that is where she would turn and hide it," he said.
He wants his identity protected, but his story told. He believes it can serve as a warning to others.
"AA has a really good slogan which is we're only as sick as our secrets. And social media makes it easy to have a lot of secrets," said therapist Micki Grimland.
Relationship therapists tell us they are seeing it all the time.
"The reason it becomes such an open avenue to cheating is because people who wouldn't normally have an affair all of a sudden they find themselves in Facebook," said therapist Lorraine Roddy-Jacobs.
Divorce attorneys are seeing it too. A recent survey found that social media is now being cited in one out of every five divorce cases in the United States.
"There has been a huge impact in not only divorce cases but all litigation focusing on marriage issues," said Earle Lilly, a Houston divorce attorney.
The cheater usually leaves plenty of evidence behind and investigators tell us it's not hard to find.
"You know, when I'm doing the internet investigations, I'm always surprised at what people are posting," said Bobbi Bacha with Blue Moon Investigations. "We get pictures of you. We have personal information about you. We have your name, age, a lot of things."
And then there are the tell-tale signs spouses say they should have seen:
- Excessive time texting or on the computer, especially at night.
- A fierce protection of the cheating spouse's cell phone.
- Quickly getting off the computer when they entered the room.
- A big change in appearance and attitude.
"Be aware of it, and pay attention to the little things because the social media things will give them another avenue to slip further and further away from that spouse or from that family," the Houston husband told us.
And finally, when it comes to socializing online, therapists say to remember this.
"You should never say anything on social media that you would not say to your spouse," said Grimland. "That you would never share any thought or feeling or experience that your spouse wouldn't be the first person that you would share that thing with."
Another tip on online openness -- share your login and password with your spouse. Also, minimize the amount of time you spend on social media to work on your real life relationships.