Freddie Prinze Jr. explains why his 20-year relationship with Sarah Michelle Gellar works

In a world where it seems like every day brings a new celebrity breakup (we were all rooting for you Miley and Liam!) it's comforting to know that some stars are in it for the long haul. We're talking about '90s heartthrob Freddie Prinze Jr. and his wife of 18 years, Buffy the Vampire Slayer Sarah Michelle Gellar.

Freddie, who you might remember from his star-making turn in She's All That, spoke to Us Weekly about their envy-inducing relationship. And while you might want him to give out a list of rules you can follow completely, the secret is that there are no rules at all when it comes to their rom-com worthy relationship.

“There’s no keys. There’s no rules. There’s nothing like that. I don’t believe in false expectations. I just believe in knowing who you are when you start a relationship. And if you don’t, then that relationship probably isn’t going to work," he said.

The couple first met in 1997 when they both starred in the horror movie I Know What You Did Last Summer. His wife recently shared their meet-cute experience on Instagram, writing that their relationship turned romantic after they met for dinner even after their friend bailed on them.

They got married on the beach in Mexico in 2002 with plenty of celebrity guests, including Shannen Doherty, Lindsay Sloane and Wilmer Valderrama. They now have two kids, Charlotte and Rocky, who they often share photos of on social media, although they cover their faces for privacy.

“For Sarah and I, we’re very private people. We try to make each other laugh, and we both kind of knew who we were,” Prinze Jr. told the magazine, adding, "Hollywood’s a crazy business ’cause there’s very few locals here. … And we can pick you out of a crowd. It’s like a lion seeing the weak gazelle. So, when you come out here, and you don’t know who you are, this business will define you and it will put its fingerprints all over you. It wants to do that. It needs to do that. And if you do know who you are, then you can kind of control your own destiny much more easily.”

The '90s hunk went on to say, “The same rule applies in a relationship. If you don’t know who you are when you get in that relationship, odds are the other person is going to have a big hand in defining what kind of person you’re going to be. Or, and worse, if you pretend to be someone else, that’s a lie you’ve got to live forever if you want that relationship to work out forever. So, knowing yourself is sort of the key to doing it.”

He also gives some advice that's useful for any couples, no matter how non-famous they are. "Sarah likes what she likes. I don’t trash reality television. I don’t trash any. If she digs it, cool...So, let your girls watch what they want to watch. Let your dudes watch what they want to watch. Don’t give them a hard time." Tell that to your significant other the next time you're 20 episodes deep into Love Island.

Both former actors have been extremely busy over their last two decades together. Gellar founded the baking company Foodstirs and her husband has been quietly releasing cookbooks. They're also starring in a dishwasher detergent ad together that encourages people to "do it every night."

We just want an invite to dinner at their house next time - we'll even help do the dishes.