Rumour has it the blonde was SO devastated her two-year-old pup couldn't join her on the Irish-leg of the tour that she was left speechless both on and off-stage.
According to The Mirror a source said: "Yogi has been ever-present throughout the tour and a constant, loyal companion... Sarah obviously wanted him to join her for the Irish dates and had correctly filled out all the paperwork to ensure Yogi was granted a passport.
"However, a recent statutory change meant the paperwork wasn't approved because Yogi wouldn't be spending sufficient time in the country." Uh oh!
The source added, "A flunky was sent to inform Sarah of the authorities' decision and did so moments before they took the stage. Sarah was devastated. She was so preoccupied with thoughts of Yogi and being without him, she forgot a few lyrics.
"Obviously Sarah does know the words and was mortified."
Hmmm, not sure we buy that excuse...