No matter how well your relationship seems to be going, there are always threats circling: financial stresses that send your harmony off-key. Divergent interests and priorities that make together-time hard to schedule. But perhaps the most potent threat comes in the form of the enemy invader – the man or woman who has the power to lure your partner into the tempting and dangerous world of infidelity. And even if your partner is a man or woman of unyielding loyalty, your own jealousy-justified or not-can create a relationship hazard. So, is your jealousy justified? Let’s take a look at the prime suspects, and see if we can’t figure out what they’ve been up to.

The Co-Worker? In most work settings, your partner has maybe hundreds, probably dozens, or at least a few opportunities to develop good relationships with people who could be potential lovers. In most cases, those relationships are more innocent than baby lambs. Still, the average office has high potential for trouble, because it’s where your partner will meet people who think alike, who battle crises side-by-side, who work in close quarters, and who have the opportunity to really get to know (and admire) each other. While it’s crazy to obsess over every person your partner works with, chances are that if you have a gut feeling about a lurking somebody, there may be something to it.
Potential Threat Level: 4 stars (out of a possible 5)

The Drunk Stranger? It’s the scenario we all fear. Our partner goes out, hangs with friends, flirts with fellow drunks, makes a bad decision, and wakes up with their underwear hanging from some stranger’s chandelier. While the scenario lends itself easily to our imaginations, the truth is that the drunk-stranger scenario isn’t as much of a threat as we make it out to be. Why? Even drunk, most of us can be savvy enough to know that the momentary adrenaline that may come from said hookup isn’t worth the long-term damage that comes later. The exception: If your partner shows a propensity to make bad, dangerous decisions when drinking. In which case, they have to change, or go.
Potential Threat Level: 1 star (unless…)

The Ex? Tough one. Some of us want nothing more to do with our exes once we break up. And some of us keep have our exes as our desktop background for years after the split. Since we’re very sensitive about the status of the ex (according to national surveys I did for Men, Love & Sex, 20 percent of us think that searching the Internet for an ex is cheating, for example), we all know the stakes. We know that our current partner used to find something attractive about the ex-so we’re vulnerable to feeling as if we’ll never live up to that prior history. While hooking back up with an ex is tempting, most of remember exactly why we broke up in the first place. Novelty is the greatest temptation toward cheating, and that’s one thing an old flame can’t offer: the lure of something new.
Potential Threat Level: 2 stars

The Opposite-Sex Friend? Drives you crazy, eh? He meets her for coffee every week. She IMs an old college buddy a few times a month. The opposite-sex friend lurks like a hungry wolf, ready to pounce at the next opportunity. While I’m convinced that men and women can both be very good at drawing the line between friendship and romance, the truth is that it’s pretty darn easy for a long-lasting friendship to turn into a secretly burning romance. In the aforementioned surveys, one-fifth of men say they secretly love their platonic friend, with many more secretly lusting after them. That doesn’t mean that your partner can’t have opposite-sex friends, but it does mean that as the friendship grows, so do the odds of trouble.