Katy Perry annoyed Scottish people at Glastonbury by not knowing what the saltire was

Katy Perry played the Pyramid stage at Glastonbury this weekend.

Her set was colourful, full of glitter, and crazy costumes - true to the Katy Perry brand.

She even crowd surfed.

Generally the crowd seemed pretty impressed with her choreography and extravagantly dressed dancers.

Until, she said something a little ignorant and offended a proud nation of Scots.

Speaking to the crowd, she said:

I can see all of you.

Even that security guard in the neon.

Way in the back by that blue flag with the X.

The "blue flag with the X" is of course the Scottish flag, also known as the Saltire.

Needless to say, she's been mocked for her lack of flag knowledge.