Justin Bieber’s mother, Pattie Mallette, celebrated her son’s first Father’s Day ahead of the birth of his first child with wife Hailey Bieber.

“Happy Father’s Day Justin,” Mallette, 49, wrote via Instagram on Sunday, June 16, alongside a handful of photos of Justin, 30, and Hailey, 27, showing off her pregnant belly. “You’ve always wanted to be a dad ever since I can remember. You have so much love to give. You’re gonna be the best daddy ever. You already are. LOVE YOU!! 🥰”

Mallette shared her post via Instagram Story as well, writing in the caption, “Happy Father’s Day my son. Soooo excited!!”

Mallette also wished Justin’s grandfather, Bruce, a happy Father’s Day in another Instagram post. “Happy Father’s Day, Papa!! I’m so grateful you’re in my life,” she wrote in the caption. “Your presence, support, and kindness have meant the world to me. Thank you for always being there, and for the love you’ve given. You’re a great dad and wonderful grandfather. I cherish you deeply. I love you so much!”

The couple announced Hailey’s pregnancy on May 9 via a joint Instagram post. While the post was not captioned, the corresponding images showed off Hailey’s baby bump. (Hailey and Justin tied the knot in 2018.)

“Hailey has always known she wanted to be a mother, so this is a dream come true,” a source exclusively told Us Weekly after the couple announced Hailey’s pregnancy last month. “Although she always knew she wanted to have a baby, she didn’t want to rush things after getting married.”

The insider added that Hailey “wanted to make sure” that she and Justin “could enjoy their alone time together as a couple” before starting a family.

“This was such a difficult secret to keep because Hailey couldn’t wait to make the big announcement,” the source told Us at the time. “Now that it’s out there she feels like she’s on cloud nine. Hailey can’t wait for the next chapter and she knows that Justin is going to make an amazing father.”

Mallette, for her part, immediately took to Instagram to share her excitement about becoming a grandma. “So I have been waiting for this day and now that they have shared it I can finally celebrate with y’all,” Mallette said via an Instagram video in May following the pregnancy announcement.

She continued, “Oh my gosh, I’m going to be a grandma. Oh my goodness! Justin and Hailey you are going to be the best parents ever and I am so excited.”