Chris Evans looked beyond comfortable this weekend at the Playboy Mansion -- where he partied in his PJs!

The "Captain America" star was photographed at the Mansion's annual Midsummer Night's Dream bash on Saturday, where he hung out with Hugh Hefner and girlfriends Shera Berchard and Anna Berglund in his pajamas.

The event this year was an Arabian Nights-themed soiree, which included camels, belly dancers and henna artists.

Also spotted at the party: A buff Michael Bay, Dane Cook, LMFAO, and "Happy Endings" stars Zach Knighton, Damon Wayans Jr. and Adam Pally.

Check out all the party pics!

Hot Videos