Have you noticed a sudden change on the way he’s acting lately? You know is different, but you just can’t put your finger on why. But those mysterious phone calls in the middle of the night? hmmm… he doesn’t have a good explanation. Is he cheating?

Well… don’t let your mind get creative until you do some more digging. When it comes to men cheating, there are several subtle changes that can take place and that women are usually unaware of until it’s too late. Here are the top 10 tell-tale signs to watch for in your man.

Via YourTango:

1. He strays from his predictable everyday behavior.
After spending time with someone for a number of months (or even years), you know their typical behavior. You know how they will act in certain situations and when they act differently, there has to be an explanation — if not cheating, then something else real and tangible. In this respondent’s case, he wasn’t doing anything strange … but he explained the sign that exposed him. When he started his affair, he would grab his phone and head into the restroom for 20-30 minutes. His excuse: He was “reading email and the news.” The only problem was, his phone bill showed something very different.

2. He has unpredictable mood swings.
Being angry instantly — or being overly nice — is a red flag. There’s no real reason for him to leave, so he has to create one. New activities that he goes to all the time, but never mentions is a glaring example. If he was going somewhere and had no reason to hide it, he would most likely share it with you. (“I need time just to be alone.”) While logical, excuses like these are usually without a reason or completely out of the norm for him.

3. He has a rapid change in weight or appearance.
Cheating men change physically. Their love handles disappear, their posture changes and their muscle tone/definition returns. It’s the body’s primal means of preparing for courtship — he’s readying himself to attract a mate. In addition, they start taking much better care of themselves and take a lot of pride in their appearance. He’s suddenly pressing his clothes, coiffing his hair and shaving daily when he didn’t before … especially when leaving the house without you. Keep reading …

4. He has an overnight change in musical taste.
There’s nothing wrong with trying new things. But when it’s out of the blue and your significant other isn’t exposed to the change, it’s a warning sign that something is amiss.

5. He remembers things wrong or loses track of the details.
As he spends more time with both of you, the memories of his time spent with his mistress and the memories of his time spent with you will start to blur together. Schedules get crossed and he won’t be able to keep track of where he was on any given day. The time he spent with another woman will be unaccounted for — often, with no explanation.

6. He needs lots of privacy.
To take time for one’s self is normal. But when it’s out of the normal pattern—or is more and more frequent—it’s a sign that something else is going in. Going into work early, leaving late, getting off the phone suddenly, taking lots of private calls from a “relative” (mom, sister, someone untrackable) are also red flags.

7. He has a drastic change in sexual appetite and style.

A sudden shift in what’s “regular” or familiar in bed — without a discussion of wanting something new — is a big warning sign of cheating. All of the men I interviewed expressed having the feeling of a huge rush of testosterone — which would manifest as a new confidence during sex. They felt strong, masculine, the embodiment of virility and like every woman wanted them. Their egos were growing daily. Keep reading …

8. He hides his financial history from you.
Most cheating men will need an untraceable way to pay for things: gifts, meals, hotels, trips, etc. Refillable credit cards, PayPal accounts, eBay purchases are all great ways to try and hide large or frequent transactions. Large, random transfers or cash withdrawals should be investigated.

9. He has new “friends” at work and/or more work responsibilities.
Office affairs are very common, especially considering how much time we spend working together. He might mention his new “friend” to dispel any suspicions you have and if you pop in to the office unexpectedly, he might even introduce you to his “coworker” to throw you off the scent. Follow your gut and pay attention to his other behaviors.

10. He’s secretive with his technology.
Technology has gotten smarter and affairs have gone high-tech. The signs used to be a new password on a cellphone or computer, a change in the password at your bank or cellphone company or cellphones being “left in the car.” But now, cheaters can fly under the radar by using technology to do their communication dirty work. Apps exist that allow text messages, online chat sessions and pictures to last for a certain amount of time (and then disappear). Pay attention to new email accounts and new apps being used on his cell phone.

While these signs aren’t foolproof signs of cheating, a few taken in combination are sure signs that something is up. My advice: don’t make accusations that you can’t back up. If you suspect it, sit him down for a long talk about your concerns.

h/t: YourTango