So that's why! Serena Williams expertly shut down a reporter during a press conference on Tuesday, Sept. 8, after she was asked why she wasn't smiling following her US Open win against sister Venus earlier that day.
"Normally, you're smiling when you win. You laugh," the reporter noted to the tennis star. "What is this tonight? Is it because you beat Venus? Are you thinking about what's coming up next?"
Williams, 33, briefly paused, looked down, and replied: "To be perfectly honest with you, I don't want to be here. I just want to be in bed right now and I have to wake up early to practice. And I don't want to answer any of these questions. You guys keep asking me the same questions… You're not making it super enjoyable. Just being honest."
As witnessed in additional video footage from the press conference, an exhausted and low-key Williams participated in the conference, and repeatedly answered questions about her sister.
Williams, also the top-ranked female tennis player in the world, inched one step closer to a Grand Slam title on Tuesday after defeating Venus in three sets.
Williams later addressed her big win against her sibling with reporters. "Obviously we are very, very tough competitors on the court," she said (via the Associated Press). "But once the match is over, the second it's done, you know, we're sisters, we're roommates, and we're all that."
She isn't the only celeb to recently shut down a reporter during an interview. Supermodel-turned-actress Cara Delevingne made waves last month after she got into it with a local Sacramento reporter while promoting her film Paper Towns.
Watch Serena shut down the reporter above!