Take a look at your go-to topics of conversation, and how you tend to interact. "If you don't talk about feelings, the future, or hardships in life, and only keep things light and fun, this is a sign of immaturity," says Hershenson. Of course, that's not to say you guys can't talk about light and fun things. But take a second to evaluate if those are the only conversations you are having.

It's certainly OK to vent to your parents, or turn to a friend when you're having a problem with your partner. But calling your mom every time something goes wrong is not exactly how couples act in mature, healthy relationships.

"If you are telling personal details about your relationship to your parents and going to them for advice, instead of speaking to each other, this is a sign of immaturity," Hershenson says. They can't fight your battles for you, so it's important to learn how to trust yourself. And to sort things out with your partner instead.

A relationship is a team effort, so it should never feel like you're competing with your partner. Or worse — keeping score. As Hershenson says, it's a sign of immaturity if you're "keeping tabs on who pays more for things and who does more in the home."

To have a true partnership, you should both be committed to sharing your time and money. And it should feel like you're both contributing to the relationship equally, without feeling like you're forcing each other.

While people might think it's cute that you two never fight, it's not a great sign. "Generally this dynamic exists because you are infatuated with each other, and are on an emotional high," counselor Monte Drenner tells Bustle. "Mature relationships have real issues that need to be addressed, and most likely there will be a difference of opinion on how to address it. The conflict that stems from resolving the issue in a healthy manner in a mature relationship makes the relationship even more mature."

One of the most mature things a person can do is keep their cool, even when they aren't getting their way. But something that's not the best sign? "You pout or get angry," Klapow says. "Either that, or you make the compromise but your attitude sucks." A compromise only counts as mature if you're doing so willingly.

Do you find yourself holding grudges? As Klapow says, this is a major sign of immaturity, since it means neither of you is willing to discuss something that went wrong, or figure out healthy ways to move past it. But instead would rather seethe and hold onto that energy. Take note if you or your partner are holding onto past arguments, and bringing them up again later, because this may not be the most constructive way to handle problems.

When mature couples get mad at each other, they figure out a way to discuss it, and then they move on. But immature couples have a way of not only holding a grudge, but also seeking revenge after the fact. As Klapow says, you might look for ways to "teach your partner a lesson." And that's not cool.

If you take to Facebook to announce your fights, or do most of your arguing via text, take it as a sign that things may need to change. "Mature people settle their issues behind closed doors," certified counselor Jonathan Bennett tells Bustle. "If your relationship problems are on display for the entire world, it's a very immature move. Airing your drama can only make any situation worse."

And same goes for text fighting. "How you fight says a lot about your relationship," he says. "The most mature method is to calmly work out your issues in person. One of the most immature ways is to go back and forth angrily over text."

Giving ultimatums and threatening to end the relationship whenever things go wrong isn't the most mature way to handle a situation. "If you're constantly threatening to end the relationship, either because you can't make up your mind what you want or as a tool to threaten your partner, it's a major sign of immaturity," Bennett says. And it can be damaging to your relationship. "Hearing these threats all the time can create insecurity and a lack of trust," he says. So if this is something you or your partner do, it may be a good idea to reflect on what intent you have behind these threats.

It takes a healthy dose of maturity to swallow your pride and say sorry. So take note if these are two words that have never been uttered in your relationship. And then consider how you might be able to feel more comfortable saying it.

As professional life coach Dr. Ty Belknap tells Bustle, "If this is you, work on saying sorry, even in situations that were not your fault. Is it more important to be right, or to be in a loving relationship?" If you've been arguing over something silly, you may already know the answer.

Similarly, if you both struggle to admit it when you're wrong, your relationship will never feel 100 percent mature. Or fair. "If you're trying to win an argument with your partner, you've already lost," couples therapist Theresa Herring, LMFT tells Bustle. "They won't feel heard or supported and, therefore, certainly aren't going to listen to you." And that is not the makings of a healthy relationship.

But, if you're both willing to swap out these habits for ones that are a little more grownup, the two of you can have a healthier relationship. And one that's fair, supportive, and mature.