She's attending her sister Jill's 20 week ultrasound, and thinks she's just finding out the gender of the baby - but you can probably tell from her face, there's another pretty big surprise in store, and we're so glad there was a camera on hand to capture her reaction!
The video opens with Jill and Kelly staring at the screen together.
'Look at the baby!' Kelly coos.
'Looks normal, right?' asks Jill's husband Shawn, who is behind the camera - and slowly but surely, her expression changes.
'Are those TWO?!' she exclaims - and then all overjoyed hell breaks loose.
'Oh my god, oh my god, oh my god!' she screams. 'I was thinking those were two heads! Oh my god Jill, wooooow, I'm so jealous!'
Her pregnant sister can barely contain herself as the reaction continues.
'Can I have one?! Can I have a baby?!' Kelly asks. 'Oh I'm so HAPPY!'
'I was thinking today if she has two, if she has two, can I have one?! That'll save me a trip! Oh, god, congratulations! Holy cow!'
'What a big deal! You guys tricked me?'
'We just found out!' Jill explains.
'You're gonna need a big van!' Kelly exclaims in return.
Watch the hilarious video in full (warning: you may need earplugs)
(Kelly's reaction starts at around one minute in!)
Once Kelly has calmed down just a tiny bit, she then takes the camera from Shawn so she can capture the happy couple's moment together as the ultrasound technician reveals the baby's genders - and now it's their turn to be surprised, because it's two boys!
It's the third pregnancy for the pair, so their family is about to get VERY big - now, can we please get Kelly's reaction to meeting the little fellas when they actually arrive?