Prince William took a break from dad duty when he stepped out in a dapper tuxedo on Thursday night to host a charity event at Windsor Castle. William, who sipped on what appeared to be a glass of wine, led the celebration by delivering a toast to commemorate the 25th anniversary of conservation charity Tusk Trust. William's friend and Tusk Trust CEO Charlie Mayhew told People magazine that the Prince was happy to be able to let loose. "He said that he was delighted and all is going well," Charlie revealed. "He was having a week off from nappies, as he's been in London all week." The elegant Party marks the end of a weeklong schedule of royal duties for William. On Wednesday, he stopped by The National Football Centre in Burton-Upon-Trent, England, to meet with members of the England women's soccer team, the Lionesses.