'I think it was 15?' Kourtney asked her, as the two played a game called Know Thy Sister
Khloe confirmed the age, revealing she had written it on her whiteboard, but not giving any further information.
Asked by Khloe if she was in 5th grade - at around ten-years-old - the mother-of-three replied with mock horror: 'What? Who do you think I am?'
When Khloe asked her '8th' it then emerged she wasn't exactly sure of her age.
'I dunno,' said Kourtney. 'I remember it being a late first kiss. But I made up for it by doing more than just kissing.'
The questioning had begun on a rather more innocent note, as the two were first asked their favorite colour.