George Michael surprised the crowd Tuesday night during Beyonce’s concert at London’s 02 Arena when he came out to perform “If I were A Boy,” with the singer. We think Bey was so excited to perform with the legend that she forgot she was lip-synching and totally screwed up.

Watch Bey’s face at the 35 second mark as she realizes she FORGOT to sing along with the track!

Watch the performance below:

Want to know what Bey looked like in high school? Click here to find out.

Beyonce was spotted shopping in a brown jumpsuit with that bed head look: