Kate Hudson was a hot mess at her 36th birthday party — because she was sticking to the theme. Over the weekend, she had a joint birthday party with jewellery designer Jennifer Meyer and fashion writer Derek Blasberg, and the whole group got into the spirit of their "hot mess" theme. Derek posted a picture of Kate and Jennifer in their outfits, saying, "Last night me and these lovely ladies had a threesome birthday party and the theme was 'Hot Mess' and none of us needed to go shopping for costumes." Kate also shared fun snaps on social media, posting a picture of the group and writing, "Let me tell ya, there were some very committed hot messes last night ;)." There were a few famous guests at the birthday bash, too, including Sara Foster and Jessica Alba. Derek and Jessica posed for a cute picture together, and he joked of the theme, "@jessicaalba was hot. I was a mess." Keep reading to see the fun party snaps, then check out how Kate celebrated with her sons.