Katy Perry and Orlando Bloom have an unbreakable bond — and the key to their romance is the sweetest thing.

Since the two first linked up in 2016, they've suffered more than a few dips over the course of their on-again, off-again relationship only to go their separate ways after just a year of dating in March 2017.

However, the couple seem to have taken a second shot at things ever since they were pictured overseas earlier this year. Rumors of their rekindled romance continued after Perry was caught wearing Bloom's face across her sleepwear, and she later alluded on American Idol that her heart was already taken by someone special.

Then, she revealed that the special someone was, in fact, her English beau, after the pair walked the red carpet together at the Gala for the Global Ocean in Monaco this week.

Dave M. Benett, Getty Images

So, what's the key to their ever-lasting love?

Privacy.

"It truly was the best decision they ever made because it reminded them how much they love each other," an insider told Entertainment Tonight. "Keeping their relationship a secret while they worked on their love for one another has completely turned things around for them."

"They had a bumpy road and their friends were worried they wouldn't make it. But that has all changed because their bond seems to get stronger every day," the source continued. "They don't mind if anyone sees them together anymore. … They are far past that now, and in fact, they seem to be celebrating their love for one another."