Private investigator says four common signs suggest your partner is cheating on you

No matter how secure you are in your relationship, the fear that your other half could cheat is one many people share deep down.

Are they really working late at the office or going out for dinner with their friend... or is there someone else?

Paranoia can be a death knell for any marriage or relationship, so how do you know for certain whether or not your partner is doing the dirty on you, I mean, even cheaters have rules to stop them from getting caught out.

Well, that's where people like Tom Martin come in.

A skilled private detective with years in the cheater hunter game, if anyone can weed out the love rats, he can.

Speaking previously to the Independent, the former federal agent revealed exactly what to look out for when it comes to those tell tale signs you're being cheated on.

You'll want to be certain before jumping to conclusions (Getty Stock Images)

What are the four signs?

According to Martin, the most common signs that suggest your partner could be cheating are:

Spending longer at work

Yep, it's a cliché for good reason. Martin says if your partner has suddenly started to spend much more tim at the office, it could be a major red flag.

Business trips

According to the private investigator, frequent 'business trips' could also be a cause for concern, especially if they have seemingly come out of nowhere.

I mean, if your boyfriend is a store manager at Aldi and starts jetting off to Paris for 'work', probably wise to be a little suss.

Less sex

Fluctuations in how much sex a couple has is completely normal, but Martin claims it could also be a tell-tale sign that your partner is actually sleeping with someone else.

Short of catching them in the act, there are a few tell tale signs to look out for in a cheater (Getty Stock Images)

Being defensive

The expert also believes that getting defensive could also be a red flag and a potential sign that your partner is hiding something from you.

In his book, 'Seeing Life through Private Eyes', Martin details his top 20 signs of infidelity, which are:

1. Sudden change of habits
2. Leaving home early and coming back late
3. Numerous business trips
4. Questionable holiday or family event absences
5. A noticeable increase in overtime
6. Unexplained spending
7. Secret social media accounts (or emails)
8. Hidden credit card bills
9. Excessive grooming or self-care
10. Smelling like someone else
11. Buying presents you haven't seen
12. Items that can't be explained - e.g. condoms in the car
13. Suddenly joining a gym
14. Missed calls from an unknown number
15. Text messages that appear coded or secretive
16. Less sex
17. Evasiveness or defensiveness
18. They tell obvious lies
19. Having a short temper
20. Dislike surprise visits (your unexpected arrival may come at an inconvenient time for a cheater)

Now, despite the above, as I mentioned earlier, paranoia is not healthy, so while Martin has flagged a few potential issues, he urges people not to jump to conclusions that could 'jeopardise a valuable relationship over what may be unfounded anxieties'.