Justin and Hailey Bieber celebrated Halloween in a very exciting way this year ... sharing their first family picture with baby Jack Blues!
The couple went the Disney route ... Hailey dressed as the popular cartoon character Kim Possible ... with Justin dressed up as Ron Stoppable and son Jack as Rufus. In the popular cartoon, Kim is a world-saving teen and Ron is her BFF sidekick. Rufus is Ron's pet mole-rat -- adorbs!
With his tiny face hidden ... Justin cradled 2-month-old Jack ... while mom gave a sweet, loving look at their bundle of joy. And yes, the couple made sure to get some snaps in of just the 2 of them -- including one pic where JB flashed his abs!
The stars announced the birth of their son on August 23 - one day after he was born - posting a snap of their baby boy's foot along with his name.
Jack was delivered by Dr. Thais Aliabadi ... according to the birth certificate, obtained by TMZ -- the same doctor who delivered babies for Khloe Kardashian and Kylie Jenner.
BTW, it's likely Jack didn't get a ton of candy on his first Halloween ... but he sure got plenty of "Awwwww"s!