After 10 years, the wife starts to think their kid looks kind of different so she decides to do a DNA test.
She finds out that the kid is actually from completely different parents:
Wife: “Honey, I have something very serious to tell you.”
Husband: “What’s up?”
Wife: “According to DNA test results, this is not our kid”
Husband: “Well you don’t remember, do you? When we were leaving the hospital, you noticed that our baby had pooped,
then you said: ‘Please go change the baby, I’ll wait for you here.’
So I went inside, got a clean one and left the dirty one there.”