Kat and Bianca's mom was 15 when they were born?
Pretty sure Walter mentions this when he is lecturing them on why they can never date as teenagers.
Later he says something like 'when you're 45' as if to say when you're my age... so if he is 45 when they are 18, that means he was 26 when they were born. So the "accident" of their birth happened when he was a 26 year-old man and the mom was only 15?
"I can't help but notice that there are skulls all over everything. Are we the baddies?"