The ability to admit when you are wrong after an argument is the number one sign that your relationship will last, according to research.

Regular date nights, twice weekly sex sessions and saying 'I love you' every night before going to sleep are also among the top five tricks to keeping the spark alive. For those who are counting, the ideal number of kisses and cuddles exchanged on any given day should not be less than five. Interestingly, working full time is more conducive to domestic harmony, with a shared taste in films and a mutual willingness to do the washing up also listed as important. The survey was conducted for the Two Together Railcard in the UK.   Here are the Top 20 signs of a great relationship in order of importance: 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