So adorable! Gwen Stefani wrote a heartfelt note about her boyfriend, Blake Shelton, in honor of his 43rd birthday on Instagram on Tuesday, June 18.

“Happy B-day to my favorite human!!! Can’t believe you’re mine,” the 49-year-old captioned a series of photos of the country crooner. “#Soooooo lucky!!!! Gx #2019 #Gemini #GreatestGuyIKnow. Thank you, Shedd Aquarium Chicago for an amazing unexpected B-day tour!!!”

During their time at the aquarium, the Oklahoma native got an unexpected kiss from a seal, but Gwen didn’t seem to mind. She even said “aw” when the mammal laid a wet one on the side of his face.

Gwen Stefani With Blake Shelton
Courtesy of Gwen Stefani/Instagram

The blonde beauty also took to her Instagram Stories to gush about her man. “Hi guys. I just want to celebrate one of the greatest humans that ever walked the planet. Happy birthday, Blake Shelton,” she said in the clip before she went in for a smooch.

Of course, fans loved Gwen’s sweet message. One person wrote, “Happy birthday, Blake!! You two should make babies,” while another echoed, “Blake is like an extremely expensive fine wine; he gets BETTER with age. So happy for you both. Excited to see you will be on next season of The Voice.” A third chimed in, writing, “Great picture!! Soooo happy he’s yours. You both got it right!! #GeminisRule.”

The Hollywood A-listers started dating in November 2015 and are still going strong. Even though the “Hollaback Girl” singer doesn’t have a ring on her finger, it seems like she is still smitten with the Grammy nominee. “[They] are in a great place and act like loved-up teenagers, it’s so cute! Their nights out together really help keep the relationship alive,” a source told Life & Style.

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#thankuGOD 4 @blakeshelton gx

A post shared by Gwen Stefani (@gwenstefani) on

The handsome hunk loves being around Gwen’s kids — she shares sons Kingston, 13, Zuma, 10, and Apollo 5, with her ex-husband, Gavin Rossdale — since he wasn’t sure if he would have children of his own. “You know, at this point in my life, I kind of had put that [aside], like, ‘I guess that wasn’t meant to be.’ And then all of a sudden it happens, one way or another, and it’s like, ‘Wow, I really missed out on a lot,’” he said on the Today show in March 2018. “Having them around — I don’t even know how to describe it. It’s so much fun.”

Aw, we ship these two so hard. Hope you had a fab day, Blake!