There is an article out there somewhere that offers over 180 ways to tell if your lover is cheating. Heaven help the one who's really working overtime and planning a surprise party for you. Do you really need over 180 tip-offs to make the case? Actually, if you've observed the right 6 clues, all the rest is just more information that either augments your already strong suspicion or confuses the issue.

1. You'll read this one in any literature about infidelity: your gut instinct is powerful and it's where you start. You'll need more than that to preserve your sanity, but trust yourself and then look and listen for more.

2. This is about their behavior towards you. They may be more affectionate, more distant, more preoccupied, or even hostile. So the change can be from one extreme to the other, but the important distinction is that the behavior is markedly different and inexplicably vacillates.

3. Your partner's appearance will become an issue. They will dress better, workout more, and watch their weight. The same thing applies to their car. A heretofore messy car will get cleaned up and looking spiffy.

4. There will be a paper trail. Check the mobile phone bill for frequent calls. Check the bank statement and the credit card receipts. A pattern will emerge that will be undeniable if you're being honest with yourself.

5. If your partner feels guilty or is trying to divert suspicion, you will receive unexpected gifts and/or flowers. If you're already suspicious, you'll experience a sinking feeling when they surprise you with something. You'll feel conflicted because they've done something nice for you, but you'll know.

6. They will work longer hours or there will be missing time. Coming home later than usual and you can't get a hold of them at odd times? They have to find time whenever they can to carry out the affair. It has to come from somewhere.

All of these behaviors and signs add up to make a pretty powerful case that someone is cheating on you. You start with the gut instinct and then discover the rest. Really, even the most clever cheater broadcasts the affair unwittingly.

Can the relationship survive? Yes and no. Yes, if you both genuinely want it to work out. The difficulties arise when only one of you wants to make the effort necessary to continue. Trust can be rebuilt. Blame will subside, as will painful and intrusive imaginings and memories. But it takes work and time. So both parties need to commit to that process. The unfaithful partner may have too much guilt (or too much pleasure!) and not be able to step up to the plate. Those who have been betrayed may not be able to forgive or forget, or allow the unfaithful one to forget—which can further destroy the relationship. If the relationship was strong at any point and there is a will, than there is a way to save it. There's more, of course, but now you know enough to make a case and begin to trust your intuition, and you know what can be done if your worst fears turn out to be true. Don't always expect a confession, but that in itself is a good sign. You may have to forge ahead and make decisions based upon what you know so far, without the benefit of having your reality validated by your partner. Trust yourself.