717,000 Brits have admitted they cheat on their partner once a year “as a treat”, according to new research.

The research from GrandNational.org.uk surveyed Brits on various pastimes they treat themselves to once per year, with 2% admitting to cheating on their spouse.

Respondents from Belfast were most likely to be disloyal to a partner (7%), with people from Southampton (6%) and Bristol (5%) proving not to be particularly faithful either.

Other slightly riskier treats include skiving off work and spending a whole day naked, with 3% of respondents admitting to doing either one on an annual basis.

Going on a holiday ranked as the top yearly indulgence, while placing a bet on events such as the Grand National also featured in the top five.

2,050 UK adults were surveyed between February 25 and March 1 by Research Without Barriers (RWB).

The research was carried out ahead of the Grand National on April 10, with almost half the country will get involved, and 13% stated it’s the only event they ever put money on.

The race is most popular in Glasgow, where three in five people back a runner in the National. Punters are also well represented in Birmingham and Liverpool (57% and 56% respectively).

A spokesperson for GrandNational.org.uk said: “The Grand National is an event that many people will put money on, even if they never normally bet.

"It’s an annual tradition, so we wanted to find out what else Brits do once per year as a treat."

They added: “While things like holidays and dining at fancy restaurants are common indulgences, the fact that a small proportion of Brits admit to cheating on their partner as a treat is particularly surprising.

"Our findings suggest that if you’re from Belfast and in a relationship, you better check on your partner immediately.”

Top activities Brits doing once per year as a treat:

  1. Go on holiday - 43%
  2. Eat at an expensive restaurant - 22%
  3. Visit friends or family - 21%
  4. Go for afternoon tea - 21%
  5. Place a bet - 19%

The study also asked Brits what activities they try to put off doing more than once per year, with 4% admitting to avoiding seeing their in-laws more than one day in 365.

Women (5%) are more likely than men (3%) to try steering clear of a mother or father in-law, while Bristol is home to those least fond of their partner’s parents (7%).

Various housework tasks dominate the list of activities people try to avoid most, but health and fitness also appears low on Brits’ agendas – over one in 10 Brits avoid exercising more than once per year (12%).

Top activities Brits try to avoid doing more than once per year:

  1. Big house clean - 29%
  2. Declutter belongings - 28%
  3. Clear the wardrobe - 25%
  4. Defrost the freezer - 25%
  5. Clear out kitchen cupboards - 24%