(CNN) Kylie Jenner may be the youngest-ever self-made billionaire. But she did NOT talk about it at the Met Gala.

The 21-year-old makeup mogul and reality star took to Twitter to respond to comments Alex Rodriguez made about their conversation at the ball.

In an interview with Sports Illustrated published Tuesday, the former professional baseball player said he and Jenner were seated at the same table at the Met Gala in May.

"Kylie was talking about Instagram and her lipstick, and how rich she is," he told the sports magazine.

Not true, Jenner shot back on Twitter. She said they -- like nearly everyone else at the time -- were talking about the television show "Game of Thrones," which was nearing its series finale.