Armie Hammer gave away a little too much information during his appearance on Jimmy Kimmel Live! on Thursday, accidentally letting it drop that he's expecting a baby boy with wife Elizabeth Chambers.
The 30-year-old Birth of a Nation star was asked if he knew the sex of his second baby -- and Kimmel expressly told him he didn't have to reveal it -- when he let it slip.
"I do know," Hammer said. "You can find out now at nine weeks, which is really bizarre. They do a blood test. They test if there are hormones in there. They go, 'Oh, you've got testosterone -- so you've either got balls or you're having a baby boy.'"
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Hammer and 34-year-old Chambers are already parents to their 1-year-old daughter, Harper. The two announced they were expecting their second child earlier this month with a sweet Instagram post.
"Ready to start the #torontointernationalfilmfestival festivities," Hammer captioned a pic of him touching his wife's baby bump. "All three of us!"
Hammer isn't the first celeb to accidentally divulge the sex of her baby to Kimmel. In March 2013, a pregnant Jessica Simpson accidentally revealed she was having a baby boy.
"It's a total different pregnancy. I just feel awful," Simpson said about her second pregnancy. "I've been vomiting. The crazy thing is I never knew that a wiener could actually make me nauseous."
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"I didn't even know what was happening," Kimmel laughed after Simpson pointed out her big slip-up. "I thought maybe you were having a girl with a penis. I don't know. Well, congratulations."
Watch the cute moment below: