1. They support each other's interests
You don't need to understand why your partner is so obsessed with Game of Thrones. Equally, they really don't need to be into tennis, cooking, or whatever it is that tickles your fancy. It's not necessary (and probably not healthy) for partners to like all of the same things, but it is important to support them and their passions. There's nothing sexier than seeing your significant other get excited about something and properly geek out over it.
2. They don't go to sleep on an argument
It can be tempting to turn the light out midway through an argument and roll over. That way you win, right? Except you go to sleep sad, confused, and angry. And you'll wake up that way, too. Some arguments need more than a quick chat before bed to fix, but if you can avoid going to sleep when you're angry at each other, you'll wake up feeling a lot better about whatever it was you were fighting about.
3. They don't give each other the silent treatment
When you're annoyed about something, it can be easier not to talk about it. That said, it's not always easy to just let it go. So instead you end up saying nothing and letting your anger bubble away under the surface. This is not good for anyone. The silent treatment is, as we've all no doubt experienced at some point, extremely effective in getting your point across. It's also a relationship killer. Communicate with your partner. Explain that you're upset. Even if you tell them that you're not ready to talk about it, airing your grievances is always healthier than bottling them up.
4. They check in with each other
We all get busy and stressed. When we do, it's easy to stop checking in with our partner. Not asking someone how their day was before you launch into a monologue about how stressful your meeting was can really take its toll on a relationship. "We're out of milk" is not a meaningful conversation. Happy couples share the little things, as well as the big.
5. They keep on top of the dull stuff
Sorting out the bills might not sound romantic, but there's inevitably a bit of admin when you've been dating a while: shared holiday payments, dinner ingredients, and a fair share of bills when you move in together. Happy couples know the best plan of action is to deal with the dull stuff quickly before it becomes something that you spend a weekend having to sort out. If that means drawing up a list of chores, or setting up some standing orders, so be it. Better now than ruining your dinner out because of a stupid fight about the bill.
6. They have their own friends
Every couple will almost certainly have mutual friends, but you don't have to be joined at the hip. There is nothing stopping you meeting friends solo, or turning down an invitation to hang out with an old pal you've not seen for ages. When you do your own thing, you have stories to tell and you get excited to see each other. If you're in each other's pockets all the time, the conversation dries up pretty quickly.
7. They don't compare themselves to other couples
So Dave and Becky are going to the Bahamas again this year. Tim and John are adopting. And Liz and Simon are getting married after only four months. All power to them, but nothing that happens in another couple's relationship has any bearing on yours. The happiest couples are going at their own pace and they're not comparing where they're at with anyone else. Do not, whatever you do, compare yourself to the happy couple on social media. There is a very glossy filter on those photos.
8. They're each other's cheerleaders
Not every dream and goal your partner has will directly impact you. Whether theirs is a fitness goal or bagging a promotion at work or just finally learning how to make a decent lasagna, the happiest couples support each other and help the other achieve their dreams. This might mean eating 15 terrible lasagnas or helping write a brilliant business plan or just meeting them with a green juice at the end of a long run. It's not what you do that matters, what matters is that you're there alongside them while they do their thing.
9. They put in the effort
Relationships can be a lot easier at the start. The honeymoon phase is all sex and flirting and staying up late talking. That's not easy to keep going, one, five, or 10 years in. There's always going to be dips and lulls in any relationship, but the happiest couples put the effort in to ensure the intimacy continues. Sex is a huge part of that, but it's not everything, and intimacy comes in a lot of different forms. Don't stop making the time and putting the energy in. Very often, the more effort you put into something, the more you get out of it.