One Direction star Harry Styles is reportedly set to serve as best man at his mother's wedding this weekend (01-02Jun13). The singer's mum Anne will exchange vows with her long-term partner Robin Twist on Saturday (01Jun13), and the boyband hunk will play a pivotal role in the ceremony. Editors at Britain's Daily Mirror report Styles will be a best man at the ceremony, along with Robin's son Mike. The singer's One Direction bandmates are also expected to attend the celebration. Styles' parents divorced when he was seven years old.