A study commissioned for the new Samsung Galaxy A-Series smartphone range has revealed that four in ten adults in a relationship regularly sneak a look at their partner’s phone behind their back to keep an eye on what they are up to.

Women are apparently the most suspicious, with 44% admitting to checking a partner’s phone in secret, compared to just 36% of men.

The study also found 34% know their partner’s mobile PIN, 39% know their email account password and 26% know their Facebook password.

Just over half even believe sharing your mobile PIN or social media passwords is a modern sign of true love or being in a committed relationship.

While six in 10 snoops have caught their partner cheating on them or talking to someone they shouldn’t be, over a third have scuppered a romantic surprise their loved one was planning.

Ines van Gennip, Marketing Director for IT & Mobile, Samsung Electronics UK & Ireland, who commissioned the research said: ”Mobile phones are such a huge part of our lives now, consumers want to stay in touch with loved ones via text, phone and social media on an affordable device without having to compromise on style or design, the launch of our sleek new Galaxy A-Series makes that all the more possible.

”Rather amusingly this research shows that suspicious partners seem to be using them quite regularly to check up on their other half on a regular basis.

”As we head towards the Valentine’s season however, it’s worth bearing in mind that you might discover something your partner is trying to keep hidden for all the right reasons, such as a secret weekend away they are planning, a special gift or perhaps even a marriage proposal!”

Top ten things partners check:

1. Text messages

2. Call history

3. Facebook private messages

4. Emails

5. Photo gallery

6. Internet history

7. WhatsApp history

8. Twitter private messages

9. Viber History

10. Skype history

The study of 2,000 Brits found almost half have gone through a partner’s phone in at least one relationship they’ve been in, with 16%admitting they have done this with pretty much everyone they have been with.