昔日情人成为网络好友合适吗?

Or we may be looking for closure. 'My ex-husband found me on Facebook, and I said sure, what the heck, and friended him,' says Lisa Bakken, a 45-year-old business manager in Grand Lake, Colo., who was married for five years. 'When the wall posted 'Lisa and Oddvar are now friends,' I thought it was hysterical. It's about time!'

Many of us are simply nostalgic. Contacting an old flame allows you to 'look back fondly on that innocent time in your life when you didn't have any significant responsibilities,' says Georgi Chase, 45, of Novato, Calif., who works at a consulting firm and looked up an old boyfriend through a networking site. 'You can go back and rediscover your 19-year-old self and wonder what she would think of the 45-year-old you.'

That's all fine and dandy. But I warn you: You are playing with fire.

For one thing, you might be surprised by what you find.
Mary Ellen Hettinger recently used LinkedIn to look up a guy she knew in college and later dated. 'We'd had all this chemistry between us for years, had a lot of fun together, but when it came down to actually making out or necking, the kissing just didn't work,' says Ms. Hettinger, 55, who lives in Amherst, N.H. and is a public-relations manager for a Girl Scout council.

So how is her old beau doing now? 'You guessed it, he's gay!' she says.

Sure, it's unsettling to find out your ex is now more wrinkled, chubby or bald -- or a different sexual orientation -- than you remember. But it isn't the worst thing that can happen.

You could discover they hate you.

You'll know they do if they ignore you. Or tell you off. Or send you a link to that Kate Miller-Heidke Facebook song that made the rounds online this summer. The Australian singer-songwriter wrote a bitingly hilarious, if vulgar, ditty about a loathed ex's unwanted friend request.

A former lover who is still hurt -- not surprising? Well, consider this: What may be most at risk when you 'poke' an ex online may be your current relationship. In a Facebook group called, appropriately, 'Facebook ruined my relationship,' a man from England explained that his wife had left him for an old school friend she had found online. 'Once she became secretive about her posts, I should have become suspicious,' he wrote.

Of course, all this isn't really the fault of the Internet. It's our fault. It's what happens when you ignore the time-honored rule on former romantic partners: Let sleeping dogs lie.

Pre-Facebook, we wouldn't have dreamed of writing a letter -- or picking up the phone and calling -- an old flame. If you went looking for a former partner, you knew you were looking for trouble.

We need new rules now.

How about these? You can look, but don't make contact. Strike an agreement with your current partner that you will each disclose any Facebook friends you have slept with. Or, like Katie Robinson, limit your online 'friends' to people of the same sex. 'It is hard enough to have a relationship without the intrusion of people from your past,' says Ms. Robinson, a 33-year-old artist in Memphis, Tenn.

Some couples share their passwords. 'If your bank accounts are common, why not your Twitter and Facebook accounts?' asks Clemson Smith Muniz, a Spanish-language sports announcer in New York.

Sound scary? Mr. Smith Muniz discovered one of the drawbacks when he checked his Twitter following -- which he spent months trying to build -- and discovered an alarming trend: It kept shrinking.

At first, he worried that people found him boring and were dropping out. He tried harder to be clever, 'tweeting' about Cuban baseball players and his dental problems. He even pleaded for readers: 'Follow me and I'll follow you.'

Then he discovered his problem: his wife.

'She told me she was going on my account and taking off women she thought were coming on to me,' says Mr. Smith Muniz, 51. She didn't care if they were old girlfriends or porn stars. 'She said she doesn't want temptation to be there,' he says. (His wife declined to be interviewed.)

Still, transparency is good for your relationship, experts say. If you are in touch with an old lover online, tell your current partner, advises Karen Gail Lewis, a marriage and family therapist in Cincinnati. You should explain why you want to touch base with your ex, she says, listen to your partner's concerns, and share any correspondence. 'It should be the two together talking about the one over there,' says Dr. Lewis.