Why's the Rushed-Husband So?

The man went abroad for six years to come back to the first time to carry a gift to see his wife, how to find his wife has a 4-year-old child at home, his first reaction is that his wife betrayed him, he thought that after 6 years away from the impossibility of giving birth to a 4-year-old child, it turns out that 6 years ago he and his wife in the two sides of the mother's handful of marriage certificate, the two were also drugged by them to produce the intersection of the next day he woke up to go!