we sang it a little bit differently:
Our second part was "oh, tumba tumba ta tumba tee" (instead of 'Tay tumba tumba ta tumba tay')

and the next part was
tumba tumba tumba tumba tumba ta tee (2X)
(no 'Ta tumba ti, Ta tumba tay' and no 'ahh ahh' part. It seems like we ended with a final "tumba" which was kind of whispered)