Katy Perry's grandmother asked a violinist in an expensive restaurant to play I Kissed A Girl.

The quirky pop star was horrified when her relative mistook the musician's classical performance for an annoying mobile phone ring tone. However, there was more embarrassment to come when the elderly woman asked the bemused man to play Katy's breakthrough hit.

The 25-year-old star wrote on her Twitter account: "Grandma asked if someone's phone was going off when it was actually a violin player.

Then player asked for requests and grandma asked for I Kissed A Girl!

But not all senior citizens leave Katy blushing. Earlier in the day she was struck speechless by the amazing fashion sense of a woman in her grandmother's nursing home.

She wrote: "Is it wrong that I wanna take a picture of a rad old lady in a amazing Chanel jacket at the old folks home?! Future meeee.(sic).