Britney Spears' sons are all grown up and looking unrecognisable as teens in rare new photo

Jayden James and Sean Preston are all grown up!

The rarely-seen teenage sons of Britney Spears have stunned fans in a series of new snaps taken at the weekend, as they spent time with their father, Kevin Federline.

The candid photos were shared on social media by CEO of Movision Entertainment, Eddie Morales - who could be seen posing in between the two boys with the group flashing big smiles for the camera.

Praising K-Fed's parenting, Morales captioned the pics: "During times of grief knowing you have #family really feels worth living.

"Talk bout seeing my nephews when they were pods smaller than my hands now look at #life how beautiful gods work is … love you bro."

Sean, 16, with a thick mass of curly hair and 15-year-old Jayden, rocking bright yellow-dyed pants, are looking very grown up from the last time we saw them.

Spears and Federline - who was once her backup dancer - tied the knot in September 2004 after a whirlwind six-month courtship. The pair divorced in 2007.

The couple share custody of the boys, with a 70-30 split in Federline's favour.