Another Awkward Parenting Moment For Britney

You'd think she'd be used to them by now.

Britney Spears was celebrating her 30th birthday with friends and family. including her sons Sean Preston, 6, and Jayden James, 5. Well-wishes from her showbiz friends poured in, including greetings from Rihanna, Christina Aguilera, Katy Perry and others. But an uncensored video message from Ke$ha quickly changed the mood from celebratory to awkward.

In the message, Ke$ha sent a message of congratulations, ending with "Happy f***ing birthday!", prompting demands of an explanation from the boys.

A red-faced Spears later tweeted to Ke$ha,  "Thanks Miss Kesha. Just watched this in bed w my boys. Now I have to explain what F---ing means!! U rock Xxoo."