Justin Bieber is to be a big brother again.

Justin Bieber's stepmother Chelsey (c) Instagram

Justin Bieber's stepmother Chelsey (c) Instagram

The 'Sorry' singer and his girlfriend Selena Gomez flew out to Jamaica earlier this week to celebrate the nuptials between his father Jeremy Bieber and Chelsey Rebelo, and now his dad - who also has Jazmyn, nine, and Jaxon, eight, from a previous relationship - has revealed he's expecting a baby with his new wife.

Jeremy shared a photo on Instagram of Chelsey, 29, showing off her growing bump in a floral bikini.

He captioned the post: "My beautiful wife and... (sic)"

Justin served as a groomsman when Jeremy and Chelsey tied the knot in an outdoor ceremony on Monday (19.02.18).

The 'Believe' hitmaker looked over the moon in several official wedding photographs shared on social media by the happy couple and their guests.

In one, he could be seen throwing his hands in the air as he rushed down the makeshift beach aisle, whilst in another he had a huge grin on his face as Jeremy and his bride took their vows.

Justin's new stepmother shared a photograph from their special day, which featured the pop star.

She wrote: "Yesterday was the most amazing day ever. I married my best friend! I love you! (sic)"

While the 23-year-old singer's dad simply captioned his photo: "Family."

Though the 'Wolves' hitmaker wasn't visible in any of the ceremony photographs, one of the of the guests shared a picture of Selena with the bride-to-be's twin nieces and two other attendees prior to the nuptials.

Justin flew to Texas on Sunday (18.02.18) to pick up Selena, 25, before they headed to the Caribbean together for the wedding.