Ah, relationships - that beautiful tango of love, trust and sometimes... shady behaviour? We've all been there: wondering if our significant other is channelling their inner James Bond and carrying out a covert mission behind our backs. You don't want to jump to conclusions, but the detective in you can't resist gathering evidence. Let's go through some 'not at all suspicious' signs that your man might be cheating, keeping it light and fun, because why not laugh while you're having a bit of an identity crisis?

Sudden phone privacyRemember when his phone used to be casually lying around, free for the taking? Now it's like he's guarding it with his life. If he suddenly needs a fingerprint, a retina scan and a security question to unlock it, girl, he's either planning a surprise party for you (unlikely) or there's something fishy going on.

Suspicion level: Using his phone on the toilet for an hour? Highly suspicious. Unless he's researching world peace solutions.

New gym routine? More like a "new person I'm trying to impress" routine.If he's suddenly obsessed with getting a six-pack, and it's not New Year's Eve, he might have someone motivating him. Especially if his last workout was running to catch the ice cream van. Sure, self-care is important, but if his gym sessions last longer than a movie marathon, it's worth raising an eyebrow.

Suspicion level: If his "gym buddy" happens to be named Sarah, you may need to follow him to the elliptical.

The over-complimenterOut of the blue, he starts complimenting you more than usual. Sounds cute, right? Maybe it is. Or it could be guilt trying to disguise itself as flattery. It's as if he thinks saying "Wow, you look beautiful today" 15 times will make you forget that he came home late smelling of an unfamiliar perfume. Nice try, dude.

Suspicion Level: Complimenting your microwave dinner like it's Michelin-star quality? Girl, he's overcompensating.

The "I work late" card is played too often.When was the last time your guy worked late? Never? Suddenly he's got projects, meetings and deadlines that seem to come out of nowhere. If "overtime" has become his new favourite excuse, you might want to consider visiting "the office" to bring him some surprise snacks (spoiler: he might not be there).

Suspicion Level: If he's "working late" on a Sunday, in a company that's closed on weekends... something's not right.

He's now too concerned with his appearanceThe guy who used to rock sweatpants and unwashed hair is suddenly obsessed with his appearance. New cologne, fresh haircuts and a strange fascination with whitening his teeth? This change could mean one of two things: either he's preparing for a reality show audition, or someone else is noticing him.

Suspicion level: If he starts using skincare products with unpronounceable names, he could be trying to impress someone who isn't you.

Changing passwords like he's in the CIAOh, so he changed his Netflix password? Weird. Then his phone pin? Super weird. How about his laptop login? Okay, now we're in suspicious territory. Unless he's under cyber attack, you've got questions that need answering.

Suspicion level: If you're suddenly locked out of everything, including your shared Spotify playlist, there's more to the story.

The magic disappearing actHave you ever noticed how he's harder to get hold of than a customer service rep? He used to text you back within minutes, but now he disappears for hours without explanation. Either he's practising his Houdini act or he's distracted by someone else.

Suspicion level: If his "phone died" every time you tried to call him, it's safe to say his phone is fine - it's his loyalty that's on life support.

Too defensive?You innocently ask him how his day was and suddenly he's offended. "Why are you interrogating me?" Er, OK. If he reacts to simple questions like he's being grilled by the FBI, it could be because he's hiding something (like an affair, perhaps?).

Suspicion level: Does he get defensive when you ask him where he went for lunch? Red flag.

The mystery friendA new "friend" keeps popping up in his stories and you've never met them. Worse, he's vague about who they are. If "Chris" or "Alex" suddenly becomes a major character in his life, but you have no idea who they are, there's a chance Chris/Alex is someone you'd rather not meet.

Suspicion level: If this "friend" is much prettier in real life than in his explanations, you're allowed to question him.

Forgets important dates

Your anniversary? Forgotten. Your birthday? Almost missed. But he can remember to text someone at 2 am? Hmm. If the guy suddenly has amnesia about things that are important to you, but his phone records show he's chatting to someone at odd hours, you have every reason to be suspicious.

Level of suspicion: If he's late for your anniversary dinner but texts his "cousin" at the exact same time... you know what's going on.

But is he really cheating?

While some of these signs could indicate sketchy behaviour, it's important not to jump to conclusions. He may just be going through a period of personal growth. But if you notice more than one of these signs, he's probably cheating.