Natasha Lyonne and Sienna Miller ooze Manhattan cool at opening of Caviar Kaspia

Sienna Miller flashes a glimpse of her toned midriff in a striped crop top and trousers in NYC

Sienna Miller cuts a stylish figure in a cosy fur jacket as she exits a nail salon in Manhattan

Sienna Miller, 40, looks stylish as she and boyfriend Oli Green, 25, leave their hotel amid PFW