A happy marriage doesn’t have to be complicated. This relationship advice is sure to keep the love and romance alive.

Marriage advice has been around since, well, marriage. While cultural values have changed and modern life presents new marital challenges, the principles of a loving marriage are timeless. Here are eight simple rules for a happy marriage.

Keep an open line of honest communication.

This is it; the single most important rule for a happy marriage is also the oldest rule in the book: Be honest. If you want to maintain trust in your marriage, you must commit to communication. It’s as simple as that. Say what’s on your mind. When you are asked a question, answer it honestly.

You’ve probably heard from your parents, or from Judge Judy, that one lie leads to another. The need to protect your lie and keep your story straight creates a snowball of deception that inevitably becomes an avalanche. Honesty works the same way. Telling the truth, even a difficult one, makes telling the next truth easier. When spouses expect the truth (and get it), marriages are much happier.

Note: Being open and honest is not a license for meanness or abuse. You chose to spend your life with this person. Be nice. Instead of starting sentences with “I hate it when…” try “I would like it if…” or “I need you to…”

Be faithful.

The completely accidental, it-just-kinda-happened fling is a myth, a work of absolute fiction. Even a drunken one-nighter with a stranger requires several decisions on your part. Cheating doesn’t happen to people—people decide to cheat.

Following this rule comes down to keeping yourself out of tempting situations. Don’t go out for drinks with your secret crush in the next cubicle. If you are unsure whether you are putting your marriage at risk, ask yourself how you would feel if your spouse were in your place. If that thought makes you uncomfortable, then you are in a bad spot. Get out of it.

Be supportive.

From the moment you say “I do,” you and your spouse are in this thing together, and as President Abraham Lincoln once said, “a house divided against itself cannot stand.”

This is not to say that you have to agree with every decision your spouse makes. Thinking your marriage will escape any disagreement is naiveté. If your spouse makes a decision you don’t like, voice your opinion (Rule 1!) but once the decision is made, stand by each other. In some cases, no one else will.

Put the couple first.

Every paycheck, you put some money into your 401K. Sometimes, it would be nice to have that cash back to spend on new clothes or a night out, but you know that the little bit of money you put away today will grow into more money tomorrow. Apply the same logic to the time you give to your spouse.

You’ve got to show up, to put in your time. That might mean doing something fun like planning a date night. That also might mean attending a company picnic and listening to the boss’ sailing story again. Whatever it is, be there with a smile on your face. The blip of time you spend now will pay off in a happy, supportive marriage.

Stay, even when it’s difficult.

Dramatic exits are great reality TV fodder, but they can wreck your marriage. Not only is stomping away childish, but it shows your spouse that you do not want to work on the marriage, that you give up. Is that really the message you want to send? Once you walk out in anger, you can never return to the same relationship.

Brag on each other.

You wouldn’t have walked down the aisle if your spouse never wowed you. Don’t let the phenomenal become familiar; don’t let the magic become commonplace. When your spouse does something remarkable, remark on it. Never let your spouse forget why you fell for them.

Have fun together.

Keep your marriage from feeling like work by having fun with your partner. Never stop doing the things you’ve always loved doing together; try to recreate some of your old dates if you want. But don’t just rely on the past, life is happening now. Keep finding new ways to share a laugh. Stepping outside your normal routine will keep you close and happy.

Don’t forget you are your own person.

One of the things that attracted your spouse to you is that you had your own interests. Don’t give up your passions just because your spouse isn’t into them. These hobbies will give you more to talk about and help keep you personally fulfilled.

Also, don’t forget about your friends. You can hang out with them without your spouse. Sometimes, you just have to reconnect with your pals. Don’t worry, your spouse won’t leave you for taking a little “me” time.

Remember to keep your eyes on the big picture. See the forest, not the trees. If both of you can stick to these rules, everything else will fall into place.