Lorde sings duet for boyfriend James Lowe's birthday

Lorde took to Instagram Wednesday to wish her boyfriend James Lowe a belated birthday.

The "Royals" singer posted a series of messages conveying a her love to the photographer.

The latest post featured Lowe covering his face he aided his famous girlfriend in singing Shaggy's "It Wasn't Me."

"I know you guys don't know as much about this dude as you do about me," Lorde wrote. "But lemme just tell you, he falls asleep at parties and then I wake him up to make him be the other half in my shaggy duet, and he does it, so basically he's the best. There's no better analogy. And no better half. LOVE YOU J!"

Lorde, 18, celebrated her two-year anniversary with the 26-year-old in April. Though the seven-year age gape has sparked controversy before, Lorde's mother seemed to show support of her daughter's relationship in posting a photo of the on Instagram.

Entertainment Tonight reported Lorde has also posted birthday notes to famous friends.

Taylor Swift received one from the Aussie in a Tumblr post that read: "Today one of my sisters turns 25. sure, she isn't a reeeal sister, and I haven't known her thaaat long, but it feels like forever - together, we've navigated our respective crazy years in work (her cheering me on as i went to my first award shows, did my first rolling stone cover, wrote for my first movie; me cheering her on as she became a pop titan and conquered the world for what felt like the thousandth time), in love, in friendship, and in growing up."