The DNA Test

After 3 years, a wife starts to think that their child looks different, so she decides to do a DNA test.

She finds out that the child is actually from completely different parents.

Wife: "Honey, I have something very serious to tell you."

Husband: "What's wrong?"

Wife: "According to DNA test results, this is not our child."

Husband: "Well don't you remember? When we were leaving the hospital, we noticed that our baby had a wet diaper and you said, 'Honey, go change the baby, I'll wait for you here'."