Justin Long has penned a heartfelt tribute to his girlfriend, actress Kate Bosworth, in time for her 40th birthday.

The note, which the 44-year-old actor shared on Instagram Monday, came with a carousel of images featuring the actress and their special moments together. In one of the photos, one can see the actress smiling while wearing a yellow bucket hat. Another image shows him kissing Bosworth on the cheek.

"She is 40!" Long wrote. "She is also the best part of my day, everyday — even when we're not together. She laughs with abandon. She makes me laugh the same — all the time. She sees beauty everywhere and in everyone. She thanks everyone - even when she's suffering, she's kind."

Long went on to share that the actress is "deeply compassionate and can't hurt anyone" but joked that she "can be a rascal."

He continued, "She loves to tease. She has the best softest lips I've ever kissed. She loves beer and football more than I do (and I love beer and football). She is the strongest person I've ever known. She's fiercely committed to the truth."

Long also noted in his post that Bosworth is "fun to work with."

He and the actress were first rumored to be dating in 2021, after working on the horror movie "House of Darkness," which was released in September of that year. However, it was three months later that Long confirmed their romance. They were spotted together in Los Angeles in March 2022, and after two months, they finally made their relationship Instagram official.

"She's the most fun to do everything with," Long noted further in his tribute. "She is genuinely curious about people and the world. She makes everything in my life better — all my favorite songs and movies, vacations and sunsets and Chinese food."

He then praised the actress for being "generous" and also for making "best cookies" during holidays.

Long concluded the post by revealing that the actress will be writing an inspirational book one day, hinting at her biography.

On the work front, Bosworth will be next seen in a movie titled "Fallout," while Long will appear next in the TV series "Goosebumps."

Kate Bosworth
Kate Bosworth arrived to ZOEasis in Palm Springs wearing a white Rachel Zoe Collection ensemble and a crossbody bag by MCM. BFA