The "Poker Face" singer, who is regularly photographed with the cup, is furious her cherished crockery is receiving more attention than she is.
She said in a radio interview: "My teacup is so famous. I yelled at her today I said, 'You're stealing my thunder go to bed!'"
"You know now it's a gimmick and it's just my teacup. That's my teacup that I like to take everywhere it makes me feel at home. It's become a celebrity."
The 23-year-old star - who refuses to drink from any other cup and saucer - says the china set helps her cope with bouts of homesickness.
She revealed: "I asked the people I work with to try to make me feel at home. I miss home sometimes and I drink a lot of tea so instead of drinking from paper I ask for china."
Earlier this week, the "Just Dance" hit maker reportedly threw a tantrum after leaving the teacup at a restaurant in London.
A source said: "She kicked up a fuss and demanded someone get her cup and saucer back."
"She wouldn't drink out of anything else. It just looked like any other cup and saucer to me and said 'Made in China' on the bottom."
