Harry Styles reportedly refers to his song writing as his "personal projects".
The 20-year-old star makes up one fifth of One Direction, alongside Niall Horan, Zayn Malik, Louis Tomlinson and Liam Payne.
In May a video seemingly showing Louis and Zayn smoking marijuana was made public and while the boys seems to have weathered the storm, Harry is apparently unhappy about their conduct.
"Everyone thinks Harry is the party boy, but he was livid about that video," a source told British magazine Heat. "Even before that scandal, he was taking a step back from the group. He's been different on the band's current stadium tour and seems to have things on his mind. He's had a separate plane taking him to gigs and is spending all his time on 'personal projects' - as he calls his song writing."
The star has been spending a great deal of time in Los Angeles and has been linked to a solo career as well as possible acting jobs. He's apparently been thinking carefully about what he wants to do with his life, especially once One Direction's current five-album deal is nearly over. There are rumours the group will release their fifth offering, speculated to be a greatest hits album, in 2015 and they are currently working on their fourth record.
"Harry is looking at his options right now. Harry's quite a loner and an old soul and finds the guys a bit immature. He prefers to spend time with his security team and Lou [Teasdale, the band's stylist and Harry's good friend]," the source said. "It doesn't feel like he has much in common with his bandmates. Harry has a new life in LA with lots of offers on the table as a solo artist."