Conor McGregor is now in training to be a father of three!
The 32-year-old shared the exciting news by posting a photo of his family dressed in matching Christmas pajamas with their son Conor Jack Jr., 3, holding up an ultrasound image.
McGregor also shares daughter Croia, who turns 2 next month, with Devlin.
"Happy Christmas everyone, from my family to yours ❤️" McGregor captioned the photo. "So much to look forward to in 2021 👶."
Devlin, also reposted the photo to her Instagram page, writing "Merry Christmas! ❤️."
Never miss a story -- sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories
Many of McGregor's fellow MMA fighters congratulated the athlete in the comments of his post.
"Congrats ma man!" wrote Chris Bungard while Kiefer Crosbie added, "Congrats brother!"
Urijah Faber replied, "Aye! Another one! Congrats guys 🏆"
The athlete's sister, Erin McGregor, also commented, "I’m so excited ❤️❤️ congratulations guys x love u."
The baby news comes nearly five months after the former UFC champion announced his engagement to Devlin after more than a decade of dating. McGregor shared a sweet Instagram photo taken after he popped the question to his longtime love.
In the celebratory photo, McGregor wrapped his arms around his now-fiancée and showed off a big smile as Devlin flashed her sparkling engagement ring.
"What a birthday, my future wife," McGregor captioned the sweet post, referring to Devlin's upcoming birthday that weekend.
Many of McGregor's colleagues took to the comment section of the post to wish the couple the best, including Artem Lobov who wrote, "Congratulations to you and Dee!!!" while Holly Holm said, "Congratulations! Many blessings ❤️."
The couple has been together since 2008. According to Page Six, Devlin grew up down the road from McGregor’s hometown in Ireland and has been by his side for over a decade since he first started his UFC career.