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Five kisses a day, a three and a half year age gap and a romantic meal once a month are among the key ingredients for a successful relationship, a survey has found.

Other crucial factors to keep your other half happy include admitting blame after an argument, sharing household chores and sex twice a week.

The list of 20 factors is designed to ensure that couple spend time together and are openly affectionate.

However, having children was not among the top 20 factors in a survey of 2,000 adults.

Sharing two hobbies, saying 'I love you' at least once a day - particularly before you go to sleep - and regarding your partner as your best friend are also signs of a lasting liaison.

If both partners work full-time that is also seen as an added bonus, the survey found.

It also emerged three quarters of the adults polled said for a relationship to be perfect the couple didn't necessarily have to be married.

The profile was created to mark the launch of the Two Together Railcard in Britain, which saves named passengers a third off rail travel when they travel together.

Spokesman Andrew Robertson said: "It's encouraging that today's perfect relationship is based on simple things such as meals out, travelling together to new places, daily kisses and telling each other 'I love you' before going to sleep.

"It's also clear that Brits aren't demanding lavish holidays or expensive presents for a relationship to be deemed faultless – it's more about appreciating the time you have together and telling each other you love them."

Other indicators of a harmonious partnership include sharing the same taste in films, sharing the cooking, having at least one romantic meal a month and being able to admit you are wrong after an argument.

The exemplary couple also stated 'talking' as the top activity they like doing together the most and travelling together to new places.

Typically the ideal couple will have a cuddle five times a day.

They will also have three mutual friends on average with it only taking fourteen months from meeting 'the one' for a relationship to become totally perfect.

For a relationship to travel the distance, the couple will also go on two romantic weekend breaks a year.

But it's not an entirely dreamy existence – bad driving, leaving dirty clothes on the floor, arguments over spending on the monthly budget and lack of washing up were all listed as things that irritate us most about our partners.

Top 20 signs of a perfect relationship, ranked in order

1. Admit you're wrong after an argument

2. Say 'I love you' before you go to sleep

3. Share household chores

4. Regular date nights

5. Take turns to cook

6. Sex twice a week

7. Share the washing up

8. Same taste in films

9. Meet through mutual friends

10. Three year, six months age gap

11. Two shared hobbies

12. Share three mutual friends

13. Three date nights a month

14. Best friends

15. Kiss five times a day

16. Cuddle five times a day

17. Have one romantic meal a month

18. Two weekend breaks a year

19. Both work full-time

20. Have the same taste in food

The Telegraph, London