The Bizarro St. Josephs?

Research suggests that, as cases of teenage pregnancies, sexual infidelity and multiple partners increase, 1 in 25 fathers could unknowingly be raising another man's child.

With improvements in genetic testing, thousands of fathers every year are discovering that “their” child is someone else's. A study by scientists from Liverpool John Moores University concludes that 4 per cent of all men are unwittingly bringing up a child they have not fathered.

Of the men who demand a paternity test because they suspect infidelity, one in four have their suspicions confirmed.

The team gives warning that the trend, known as “paternal discrepancy”, poses serious implications for the future of the family.

Link.

"Paternal discrepancy." Har har. That's rich. Make it scientific, make it sterile. Then it doesn't hurt so much.