Lenny Kravitz and 'brother' Jason Momoa share a sweet exchange while celebrating the 'Aquaman' star's birthday

• Lenny Kravitz posted a sweet message on social media in honor of Jason Momoa's 42nd birthday.
• In response, Momoa said: "love u madly. mahalo nui loa."
• The stars have referred to each other as brothers and spoken fondly of their blended family.

Lenny Kravitz and Jason Momoa had a sweet exchange on social media after the musician posted a heartfelt tribute for the "Aquaman" star's 42nd birthday.

On Sunday, Kravitz posted a black-and-white image of himself with Momoa, which was taken by photographer Mark Seliger.

"Happy Birthday, @prideofgypsies. I'm proud to call you my brother. One love. One family," he captioned the post on Instagram and Twitter.

In response, the "Game of Thrones" alum commented on the Instagram post, "love u madly. mahalo nui loa," followed by two red heart emojis. The latter phrase is Hawaiian for "thank you so very much."

This isn't the first time the two stars have shared kind words about each other and their blended family.

Kravitz was previously married to "High Fidelity" star Lisa Bonet from 1987 to 1993. They share a daughter named Zoë Kravitz, who followed in her parents' footsteps and pursued a career in Hollywood.

Momoa met Bonet in 2004 at a jazz club in LA, welcomed two children together named Lola and Nakoa-Wolf, and got legally married in 2017.

Kravitz referred to them as "one big happy family" during an episode of Oprah Winfrey's "Master Class." The "Fly Away" singer also told People and Men's Health that he loved Momoa when he first met the actor at the onset of the "See" star's relationship with Bonet.

"People can't believe how tight Jason and I are, or how tight I still am with Zoë's mom, how we all relate," Kravitz told Men's Health."We just do it because that's what you do. You let love rule, right?"