EXCLUSIVE! 'Reign' Sneak Peek: Mary's Pregnant! (But Catherine Has Known All Along...)

Long may she 'Reign' — Mary, Queen of Scots is finally pregnant!

Oh baby — this is awkward.

It's no secret that Reign's leading lady Mary (Adelaide Kane) has been desperately trying to get pregnant for months, and in tonight's all-new episode fans are in for a shocking revelation: Not only will Mary discover that she finally has a royal bun in the oven, but Catherine (Megan Follows) knew this news way before Mary did — and we've got your exclusive sneak peek to prove it.

Adding to the uncomfortable, Catherine barges in to express her excitement at being a grandma in the middle of Mary's love-making celebrations with Francis (Toby Regbo)! (Who else thinks Catherine is most definitely in the lead for most overbearing mother on TV?)

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So how could Catherine tell that Mary is with child? Her spies, of course. Oh, and this 16th century pregnancy test: "A few weeks ago I had your chamber-pot tested," Catherine shamelessly admits. "It's the usual exam, it's horse urine and wine — it's very reliable."

And despite the fact that her daughter-in-law in laying naked in bed with her son, Catherine offers Mary one particularly amazing piece of advice: "Your figure is going to go to hell anyways so you might as well eat up. You are feeding the future king of France."

Take a look at our exclusive sneak peek of tonight's episode to see all of the boundary-crossing baby buzz for yourself!

Reign airs Thursdays at 9 p.m. on The CW.

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