The cat's out of the bag!

Armie Hammer may have just revealed a little too much during an appearance on Jimmy Kimmel Live!

The 30-year-old, who's expecting his second child with wife Elizabeth Chambers, accidentally dished on his baby's sex during the interview.

“You can find out now at nine weeks, which is really bizarre,” he said. “They do a blood test. It’s crazy. They test if there’s hormones in there. They go, ‘Oh, you’ve got testosterone.’ So you either have balls or you’re having a baby boy.”

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armie hammer jimmy kimmel live getty

And the actor, who's already father to daughter Harper, 21 months, didn't stop there, discussing possible names for his future son.

"We’re thinking Jack, Jack Hammer," The Social Network star joked. "Michael Charles and he can just go by M.C."

But Armie quickly realized he had spilled the beans. "I think I just gave away our baby name," he said. “I’m in so much trouble!"

Check out the whole hilarious interview below:

https://www.youtube.com/watch?v=ERnVfGrRuOo