Beyonce embarrassed a princess. Apparently, she's not quite royal enough to show the correct amount of tact. When British royal Princess Eugenie had a mic shoved in her face, the girl either drew a blank or couldn't perform.

Beyonce played six London concerts. She customarily calls on audience members to sing the hooks of certain songs. In this show, she asked audience members to sing the "to the left, to the left" refrain in "Irreplaceable." What was not customary is that she shoved her mic in a princess's face...who may have been a little too stodgy (or British) to get down.

Or just, you know, lived under a rock and didn't know the lyrics, or maybe shy, or mortified, or, well... white. Speculations abound. It's most likely the latter.

Eugenia, 23, is the daughter of Andrew and Sarah Fergueson and sixth in line to the throne. Beyonce probably didn't recognize her. But it's not the first time she's behaved like a diva this tour.

She has dates around the globe for her Mrs. Carter World Tour, which kicked off in Febuary, but has banned photographers - which some say is a response to photos Beyonce was upset about during her Super Bowl performance.

About the incident in London, "It was hilarious," a source told The Mirror. "Eugenie was on the front row with Kate Middleton's brother, James, and his new girlfriend, Donna Air, plus designers Matthew Williamson and Patrick Cox. She was really excitable and filming the whole thing on her iPhone like any other fan."

"Beyoncé clearly didn't recognize her, so when it came to 'Irreplaceable' and the part where she picks an audience member to join in with her, she simply chose the first woman she could reach," the source continued.

When Eugenie went beet-red and ducked, Beyoncé had to quickly fill in the missing lyrics and find a new, more pliable audience member to shove her mic in the face of.

"All of Eugenie's friends were teasing her about her stage fright for hours afterward."

Princess Eugenie and Beyoncé have not commented on the incident.