Los Angeles: One Direction star Louis Tomlinson, who welcomed his first child with former girlfriend and stylist Briana Jungwirth last week, has reportedly named him Sydney Rain. "Louis and Briana are yet to file a birth certificate but they've agreed on the name Sydney Rain. It will be rubber-stamped in the next five days," a source told The Sun newspaper, reports aceshowbiz.com. However, "it's not yet known whether the baby boy will take Briana's surname or Tomlinson", the source added. As Tomlinson is no longer in relationship with Jungwirth, they have to resolve custody of the child, who was born on January 22. "There's already a lot of talk about who is going to pay what. The family have slightly exaggerated expectations of what Louis should be contributing every month," said the source.