Harry Styles performed a cover of Britney Spears‘ ‘Toxic’ at his second Halloween show over the weekend – you can watch it below.The soloist and former One Direction singer delivered his rendition of the 2004 pop classic at Madison Square Garden in New York City last night (October 31) during the second of his ‘Harryween Fancy Dress Party’ gigs.Dressed in a clown costume, Styles launched into the Britney cover during the show’s encore after performing ‘Medicine’, an unreleased track meant for