All the drugs she is back on seems to have her weight loss down, how long will it last (not long). Lily Allen performed on the opening day of the Rock Werchter Festival in a leopard-print bra and leggings.Over the next two months, she is also lined up to perform at the Roskilde Festival in Denmark this weekend, the Montreux Jazz Festival in Switzerland, the Benicassim Festival in Spain and Fuji Rock in Japan.