Rumer Willis Celebrates BF Derek Richard Thomas' First Birthday Since Becoming A Dad

Rumer Willis is rounding up the month of May on a note of celebration, one month after announcing the birth of her daughter Louetta Isley Thomas Willis.

The overjoyed mother shares the little one with musician Derek Richard Thomas who recently marked his first Birthday since becoming a dad.

In honor of the milestone, Rumer took her time to proudly express gratitude in a lengthy sentimental tribute, to have a partner like Derek, who is excellent at everything, including being a dad.

Rumer went all out for her baby daddy's 29th Birthday as she took to Instagram to celebrate him with her one million followers.

Alongside ten heartwarming photos featuring the celebrant in different scenarios, including a few of him lying in bed with their newborn daughter Lou, the proud girlfriend declared in the caption, "Happy Birthday, my sweet love @derekrichardthomas. Last year, we were still discovering each other. And now, this year, we celebrate with this beautiful girl we made."

The "Sorority Row" actress further called the artist "such a gift." She listed several of his charming characteristics she loved, including the way he giggles and makes her laugh whenever she gets "sad and grumpy."  

She wrote a few more cherishable things about him, adding, "I love your passion for music and soil and your desire to learn. I love your silliness, and you're always trying to make Lou and me smile."

Additionally, Rumer loved how the music star cooked and ate his tacos daily while being thankful for the chance for them to be "kids together and parents to this magical little girl." Gushing more about Derek, she penned, "I love that you are my partner in crime in this wild adventure. We love it when you sing to us. It's why I fell in love with you before I knew anything about you, even your name."

The "Hostage" actress added, "You truly have such a gift, and I can't wait to see you shine this year even brighter than you already do."

As Derek celebrated the new age, Rumer noted that she had seen him "grow and navigate through so much," such as "opening for the stones, producing three albums, navigating the journey in fatherhood, planting our garden, and building our home together."

She was thankful for him in her and Lou's life and called him "such a great dad," whom their daughter was fortunate to have. The 34-year-old acknowledged that it was "just the beginning of the expansion of you and your dreams" before proclaiming, "What a privilege it is to walk beside you on this journey as your best friend and true love."

Rounding up the tribute, she sent love from herself and their baby daughter before jokingly apologizing for being "such a creep" and taking too many pictures of him sleeping.

The beautiful post was met with thousands of reactions, including one from the celebrant himself, who led the remarks with, "I love you so much, baby ❤️❤️❤️." Afan also wished him, "Happy bday!!! Lots of health, love, happiness, and an amazing life with your family??????."

The celebration comes more than a month after Rumer, and Thomas announced the birth of their daughter on Instagram. The daughter of Hollywood veterans, Bruce Willis and Demi Moore, blessed her followers with a lovely photo of the newborn and shared her full name in the caption, calling her "pure magic."

The "90210" star also mentioned the tot's birth date, Tuesday, April 18, before confessing that she was more than the couple ever dreamed of.

Rumer never tires of saying the best things about her man, just like she did during her pregnancy, appreciating Derek's ever-supportive nature.

While speaking with PEOPLE about her partnership with the clothing brand, NakedCashmere, she touched on how loving her man has been since the onset of her pregnancy.

"Oh, my God. He's an angel," the actress said. "Cooks every meal for me, brings me water, [he] is so sweet. He's been so lovely, and he's just so excited to be a dad, and we're both just so delighted to meet whoever this little person is."

She raved more about Derek, claiming she had found her perfect significant other and believed strongly that he would be a fantastic father.