Recent infidelity studies have shown that around 10% of Canadians have cheated on their spouse, so it is no wonder that many people have worries about the sanctity of marriage.

There are so many reasons why women and men, both married and unmarried, look for intimacy outside their existing relationship, and while those reasons might never be uncovered, it is true to say that eventually most cheaters get caught.

Even though infidelity is so widespread, many people still have no idea that their partner is cheating on them, however if you think your partner might be being unfaithful, you should look for these 13 signs that your gut instinct is correct.

1. Missing in Action

While most couples don't feel the need to constantly stay in contact with their partner, if you have noticed that they never seem to answer your calls, respond to your texts or pick up your emails, you may well be right to assume that there is something going on.

Do they promise that they will ring you, but then you find that you're waiting around for days before that call finally comes?

Or do you find that your partner is going away on holidays with friends without taking you along and then “forgets” to communicate with you during their trip?

Perhaps your partner travels away “on business” but conveniently forgets to let you know the place in which they're staying?

All of these are signs that there may be a potential problem.

2. They Never Put Their Phone Down

These days, it's true to say that many people spend a lot of time on their phone, but most of them also know that sometimes they need to put it down and get on with their everyday life.

If your partner always takes their phone with them into the bathroom, or carries it everywhere with them as if they had it glued to their hand, it is possible that they don't want you to answer their calls or see the messages that they are sending.

Such behavior seems suspicious, and something may well be going on.

3. Is Their Phone on Airplane Mode?

Has your partner just started setting their phone on airplane mode?

If so, you need to ask why they might want to stop you from using it.

Are they keeping secrets from you?

4. Lots of Opposite Sex Facebook Friends

Of course everyone has friends on Facebook who are of the opposite sex, but if your partner has countless numbers of them and tells you that they are all cousins, workmates, old friends and classmates, you may start to wonder whether they are telling you the truth.

5. Always Working Late

Although everybody sometimes has to work late, if your partner seems to always be staying at the office late into the night without discussing the job that's taking up so much of their time, you might be sharing your partner with someone else.

Working late is well known as the oldest excuse in the book, so look beyond the potential lie – it's important to explore the matter fully to find out whether they're really telling the truth about their working exploits.

6. Expecting the Unexpected

Perhaps your partner has been especially nice of late, giving you compliments for no apparent reason.

If they have started buying you romantic and unexpected gifts, or are always taking you for dinner at fancy restaurants, this could be a sign that they are feeling guilty about something.

Alternatively, if your partner has recently become irritable and paranoid, this could also be a sign of a guilty conscience.

If you've found that your partner is snapping at you for simply making a casual comment, or if they are calling you neurotic, overbearing or annoying, you can take these as a red flag and it could be about time to let your relationship go.

7. Put Downs and Criticism

Has your partner started to put you down all the time, or call you names?

Have they begun complaining about your choice of clothing, your beliefs or your quirky behaviours?

If they are finding fault with the way you look, the way you live or even the job you do, this could be their way of saying that they want to end the relationship as they want to get together with somebody else.

8. No Dates, but They Still Want Sex

Has your relationship deteriorated to such as point where you no longer go on dates but then you get a call at two in the morning asking if they can come round?

If that sounds all too familiar, it's very possible your partner has been out with somebody else and has been hoping that they were going to get lucky.

Once they get a refusal, it is all too easy to give you a call knowing that you will be there for back up sex at any time.

It's possible your partner even thinks that, instead of being in a proper relationship with you, you are actually friends with benefits, and this can only lead to a lot of pain, especially if you're hoping for a full time exclusive commitment.

9. Ever-Changing Plans

Take it as a warning if suddenly you discover that your partner is cancelling dates frequently, making excuses such as “I've suddenly got something to finish”, “somebody needs me to help”, or even “I don't feel well” etc.

All of these are especially transparent excuses.

10. Suddenly Smartening Up

Has your partner always been somewhat lacklustre in the cleanliness department, or a slob when it comes to their appearance, but suddenly they have begun keeping their house spotlessly clean or they've started dressing smartly?

If that's the case, take care – they may be seeing someone behind your back.

If you're worried that you are being cheated on, you should pay them a visit without letting them know you're coming – you may just catch them in the act.

11. Changes in the Bedroom

One of the key signs that your partner is cheating is when their sexual habits unexpectedly change.

If they have begun initiating sex differently or are keen to try something they never have before, it's only normal to start to wonder where they have got the idea from.

Perhaps their sex drive has suddenly increased or maybe they no longer seem interested – however things have changed in the bedroom, you should always take notice.

12. Hidden Online Accounts

Have you found out that your partner has been hiding an online account that you believed had already been deleted?

A discovery of this nature suggests that they may be looking for someone else.

13. Two Places at Once

Cheating on your partner is never easy and eventually your partner is sure to slip up.

Telling lies and keeping track of deceptions takes a lot of juggling, so if they tell you that they were eating at a friend's house at a particular time and then, on another occasion, mention that they were at work at the same time, you should start looking more deeply into the matter.

After all, there is no way that they could be in both places at once!

If you've discovered that your partner is being unfaithful, it's time to move on to pastures new.