COLORADO SPRINGS, COLO. -- Social networking sites -- like Facebook and MySpace -- are considered great tools to keep in touch.

But many therapists are noticing an increase in relationship problems stemming from these sites.

Carol Reinert, a psychotherapist in Colorado Springs, says about a third of the divorce cases she sees are somehow connected to social networking.

"It's not that unusual at all," says Reinert, "In fact, it's becoming more and more common."

Sometimes a spouse ends up leaving their husband or wife for someone they developed a relationship with online.

Other times, there is a mistrust or jealous factor that comes from a partner spending too much time on the computer.

Most of the people FOX21 News interviewed admit they have -- or at least have wanted -- to look up an old flame on the internet.

Reinert says that desire to go back in times often creates an energy, addictiveness and excitement of being noticed again.

"It appears really innocent at first, and then just a couple of key works can send in down another path," says Reinert.

FOX21 News met Brian Louf, a Colorado Springs resident who says his wife left him for a man she reconnected with on Facebook.

"She had known him since first grade," says Louf.  "He was a police officer in her home town."

After seventeen and a half years of marriage Louf's wife decided to file for divorce and move to Massachusetts to live with her Facebook "friend", leaving behind her three children.

They are now engaged to be married.

Louf knows he's not alone.

"I have talked to people who had relationships that were pretty much destroyed as a result of social networking," says Louf, "and for some it was pretty devastating."

Therapists say couples need to be aware that chatting online with someone of the opposite sex can sometimes lead to somewhere they didn't anticipate it would go.

"Just having contact with someone on Facebook from your past doesn't mean that it's going to turn in to anything," says Reinert.  "But, I think people need to be conscientious about how they would feel if it were in reverse."