1. You will get a little bit fat when you're in a stable relationship with somebody you love. It's like a happy tax.
2. Telling somebody you really, really care about that you no longer love them is painful and confusing. It will break your heart. But see below.
3. Being told by somebody you really, really care about that they no longer love you is even more painful and more confusing. It will break your heart harder. It is worse.
4. Complaining about your partner's family to your partner, even if they deserve to be complained about, is a bad idea.
5. Hand jobs are something people never really grow out of. You should have a good one in your repertoire.
6. People – even nice, good, kind people – need boundaries to keep them in check.
7. Men move on quicker than women when a relationship ends.
8. Giving people exactly what they say they want is very effective. If your partner says "I need space", give it to them. How do you like them apples?
9. Getting back together can end happily but it takes boring discipline and boring forgiveness.
10. Thinking things like, I wonder how I would feel if my partner died means the jig is up. People in happy relationships know exactly how they would feel if their partner died.
11. Going to bed angry is actually sometimes a very good idea. Two o'clock in the morning is not the time to resolve arguments, which often resolve themselves overnight anyway.
12. Most people end up married or in long-term relationships. So single time is for the fun stuff: box sets that nobody else likes, threesomes, Berlin…
13. It takes men longer to fall in love than it takes women (women just *know* quicker), but once a man is in love, he'll stay that way for a long time.
14. Being "good at sex" has very little to do with being flexible or having a perfect body or reading sex tips. It is basically to do with being "up for it".
15. Hearing yourself say "Look, I know I'm acting crazy…" means it's time to rethink your strategy.
16. Nobody – well, nobody besides really old people, and even then the evidence is spurious – dies of a broken heart.
17. Fighting and bickering in a relationship is addictive. Occasionally it's even fun. It's not a good idea though.
18. Sometimes it can take a woman a really long time to orgasm or she won't orgasm at all. Don't worry about it too much. You two will get there next time.
19. Sometimes it can take a man a really long time to orgasm or he won't orgasm at all. (Yes, really.) Don't worry about it too much. You two will get there next time.
20. It is wise to buy as big a bed as you can afford when you move in together. Spooning is fun but you want options.
21. When somebody says "I just don't feel I can commit to somebody right now", they're probably around two months away from committing to somebody else.
22. It is possible to be good friends with an ex in a purely platonic way.
23. Relationships are hard and it takes work and love hurts. But it shouldn't be too hard, too much work, or too hurtful.
24. Everyone drunk dials. But four times a year should be your limit.
25. Having sex with people who are mean to you is always a bad idea.