Throughout history it's been easy to recognize infidelity, even if you personally haven't experienced it. If you've ever been to the movies or watched a soap opera, you have some idea of what it looks like: the surreptitious glances, the hurried meetings in unoccupied hallways, the secret gestures of affection, the "Who, me?" look.

Yes, you may think you know what cheating looks like, but the fact is that infidelity has changed in the last two decades. It involves all kinds of communication, interactions and hooking up that neither Shakespeare nor D.H. Lawrence could have ever dreamed up, and it's harder than ever to figure out whether your mate is violating your trust.

So forget the advice about looking for lipstick on his collar. Here are some tips for figuring out whether your true love is staying true in the electronic age.

1. Private phone calls. Does he go off into another room to answer his cell phone? Of course, if your mate works for the CIA, then privacy might be necessary. But if there's no special person outside of your relationship, then there's no special reason why all conversations shouldn't be public. You may not care to hear discussions about how the neighbor just bought a new leaf blower, but if it were an innocent conversation, your mate wouldn't be running into the next room to take it.

2. Erased history. Do they frequently erase text messages or the call list on their cell phone? The, "Oops, I'd love to show you who called, but I just erased the inbox" excuse runs thin after a while. It's just not human nature to meticulously erase lists of calls, and often doing so may be a sign that there's someone sending those texts besides work or family.

3. Private access. Have they recently changed their password or email, or otherwise denied you access. About a decade ago, I counseled a 75-year-old man whose wife threatened divorce because she discovered his emotional affair after she intercepted a birthday card from another woman. Before telephones or computers, the unfaithful mate would frequently communicate through the postal service. Now, however, things have changed and many affairs are conducted via email correspondence. Couples with nothing to hide should not be hiding email accounts from each other.

4. Powering down. Do they frequently shut down the computer when you come into the room? Chat rooms offer a wonderful way to establish intimacy, which is great if you want to share feelings about having a loved one at war or how to cope with chronic illness. But when chatting is used to establish intimate connections between two people who have an emotional or physical connection, its wrong. Anything that your significant other is willing to chat about should be something that you should be able to see.

5. Late night logons. Is your mate on the computer late at night and then their "history" is erased the next day? Some affairs don't ever have to include meeting a person face-to-face (although more often than not, rendezvous do happen eventually). If your mate is going on sites to "meet" people, or unscrupulous sites that involve live chat, then there's a good likelihood that the connections being made can unravel your commitment.

Being discreet or meticulous about your electronic life doesn't prove that someone's having an affair, but if you see any warning signs, you should bring it to your partner's attention right away. If there is an affair going on, the sooner you know the better. But if there isn't, then this would be a good time to talk about who should be allowed to electronically intrude into your relationship, and what you should do together to preserve your bond.