"People in successful relationships have a ratio of 5:1 positive to negative thoughts about their partner," Luke Carrangis, clinical psychologist and founder of Mindview Psychology, tells Bustle. If this ratio is tipped towards the negative, you're more likely to view all of your partner's actions through a negative lens. For instance, you may become suspicious over their random acts of thoughtfulness or find mistakes in the little things they do. But when you see your partner through a positive light, you become more grateful and appreciative of them. It's why Carrangis says, "This positive mindset is crucial for long-lasting relationships."

You may not always agree with your partner. But staying kind during fights is what separates the couples that last from the ones that don't. When they work through conflict together, Carrangis says they stay gentle. "They tell their partner how they feel, and avoid criticism and blame," he says. "Couples who handle conflict with an open-mind, mutual respect, and even a sense of humor are more likely to prevent relationship meltdown and live happily ever after."

There's nothing wrong with wanting to spend a lot of time with your partner. But it's also important to do your own thing and live a life that doesn't solely revolve around your partner or relationship. "Having your own separate interests will keep you in your own lane and have you filling up your own cup," Claire Byrne, heartbreak coach and poadcast host, tells Bustle. "Remember that the only person who can truly fulfill your needs is yourself." It will also keep your relationship dynamic healthy and more balanced.

When there's emotional safety in your relationship, there's no judgment. You can be vulnerable with your partner, Byrne says. Your partner provides you with a safe space to unload and you do the same for them. You can comfortably express your needs, secrets, and any issues you're having because you know your partner will listen. They may not always agree with what you have to say, but they're always willing to listen and work things out with you.

"If your partner doesn't think you're funny or doesn't make you laugh, you could probably last, but how fun would that be?" Byrne says. "Fun is a great way to make a relationship last." It's true. As studies have found, laughter can benefit your relationship. A 2016 study published in the journal Personal Relationships also found that couples who create laughter together are typically more satisfied in their relationships overall.

When you accept your partner for who they are, your relationship is more likely to be harmonious long-term. "People generally feel empowered to become the best version of themselves when they feel accepted and supported," Myles Scott, dating and transformation coach, tells Bustle. "If you don't accept them but continue to stay in the relationship, you will naturally try to control them to fit into a box that you deem acceptable." It's important to remember that the only person you have control over is yourself. Attempting to change your partner in any way will only lead to frustration.

Relationships aren't always easy. But if you have a strong foundation of friendship, it can help you overcome any challenges that come your way. As Jordan Madison, LGMFT, therapist with Friends in Transition Counseling Services, LLC, tells Bustle, there are going to be days when you won't be feeling very affectionate towards your partner. That's where your foundation of friendship comes in handy. "Even if you don’t feel like being the best romantic partner right now, you always have the friendship between you two to fall back on," she says. No matter what, you're always going to have care and respect for each other.

"Many couples say the secret to lasting so long, has been forgiveness," Madison says. "Being able to forgive your partner is a necessity if you want the relationship to make it." The reality is, no one is perfect. Both you and your partner are going to make your share of mistakes, which is OK. Mistakes help us grow. So it's important to learn how to forgive within reason. If your partner continues to disrespect you or your boundaries, you may want to re-evaluate your situation. But if your partner is sincerely apologetic, there's no reason to hold on to their mistakes.

You can love, trust, and have a close relationship with many different people in your life. But as Madison says, "Romance is the main thing that sets your relationship with your partner apart from anyone else." It's not easy to keep the spark alive. It's something that needs to be worked on if you don't want to fall into a rut. When there's romance in your relationship, you'll always feel desired, cared for and prioritized. It can also help to keep your relationship passionate and intimate.

Maintaining a long-term relationship isn't always going to be easy and not every couple is going to make it. But if your relationship has these traits, there's a really good chance that it will last.