Kourtney Kardashian's 7-month-old son, Mason, has been teething.
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"Mason has 2 teeth!!!!!!!! Yay!" wrote his proud aunt, Khloe, 26, on Twitter Tuesday.
PHOTOS: The Kardashian sisters as kids
Kim, 29, was out of the loop. "I thought just one? Kourt just sent me a pic! I see just one! This is so exciting!" she posted on Twitter.
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A few minutes later, she corrected herself, "Nevermind Kourt just said 2! Woo whooo."