Tennis star Serena Williams gave a brutally honest response when asked why she wasn't smiling at a press conference after beating her sister Venus in the US Open on Tuesday.

The tennis number one became one of the many women questioned about not smiling when a male journalist suggested Williams was looking glum because she had defeated her sister.

"You just won a match. Normally you smile when you win. You come in here, you laugh," he said. "What happens tonight? Is it because you beat Venus or because you're thinking about what is going on next? What’s wrong?”

"To be perfectly honest with you, I don't want to be here," she replied. "I just want to be in bed right now and I have to wake up early to practice. I don't want to answer any of these questions, and you guys keep asking me the same questions. It's not really ... you're not making it super enjoyable."

She then added: "Just being honest."

A reporter asked her why she didn't smile and laugh after the match...this was Serena's response LMAO #TheQueen Posted by Aaron Squintz Davis on Wednesday, 9 September 2015

Williams, who continues to be the defending champion at seven tournaments, took on negative comments about her body shape when she appeared on Good Morning America last week.

"I love that I’m a full woman and I am strong, and I’m powerful, and I’m beautiful at the same time, and there’s nothing wrong like that," she said.