The drop-dead gorgeous model was papped prancing around the beach in an itsy bitsy teeny weeny white with no polka dots bikini while shooting scenes for her upcoming film The Other Woman.
Kate - who turned 21 (we know right!?) on Monday - was filming with co-star Nikolaj Coster-Waldau for the flick, which also stars Cameron Diaz and Leslie Mann, in The Hamptons, New York.
And while Kate looked fab, even with her hair all over her face, we couldn't help but find ourselves a little distracted by how glorious the weather was. Well jel.
Less about the weather, here's more Kate...