Tomlinson, 23, has spoken out about how difficult he found Zayn leaving the band and explained that he felt the most upset out of his bandmates - Harry Styles, Niall Horan and Liam Payne, reported Contactmusic.
"It was hard. I think maybe for me the most. But he wanted to be happy and he wasn't.
"Everything had always been good and then something bad happens and you have to make decisions, you have to work out what you want and it makes you really know what you want. We all knew we wanted this," he said.