Almost right! Since it's plural (mamma och pappa), the adjective becomes upptagna.
This guy family just keeps growing, one lesson ago he had only six siblings. I hope this doesn't keep escalating, I saw tusen in one of the next lessons.
There’s an Israeli joke about a similar concept:
Three men are waiting outside of the maternity ward. The doctor comes out and says, ‘Mr. Cohen?’
One man stands up and says, ‘Yes?’
‘Everything’s fine, your wife just gave birth to a healthy quadruple.’
‘Oh... Thank God... and heh, wouldn’t you know, I live in Kiryàt ‘Arbá [a settlement near Hebron in Judæa, in the West Bank; the name literally means ‘Town of the Four’]...’
He comes in to see his wife, and the doctor goes back to help another mother. Shortly after he comes back out and says, ‘Mr. Levi?’
Another man stands up and says, ‘Yes?’
‘Everything’s fine, your wife just gave birth to a healthy octuple.’
‘Oh... That’s great to hear... And wouldn’t you know it, I live in Kiryàt Shmoná [a town near the Lebanese border; the name literally means ‘Town of the Eight’]...’
As he walks in to see his wife, the third man takes his belongings and gets ready to dash off.
‘Hey! Sir! where are you going?!’
‘I live in Alfei Menashe [a town near the Green Line, in Samaria; the name literally means ‘The Thousands of Menashe’]!’