Liam Payne's girlfriend is recalling the late One Direction member's final days ... and revealing why she left him behind in Argentina before his death.

Kate Cassidy explains why she just did a new interview with The Sun following the One Direction star's death, in which she opened up about his "headspace," their relationship and how she found out he died.

Kate Cassidy is opening up about her boyfriend Liam Payne's final days for the first time, nearly four months after his death.