Are you seeing double?
Twin brothers Craig and Mark Sanders met twin sisters Diane and Darlene Nettermeyer at the Twins Festival in Twinsberg, Ohio. Craig and Diane fell in love, and so did Mark and Darlene. Eventually, they got married in the same ceremony, moved into adjoining houses, and Diane and Craig had twin boys!
Monozygotic ("identical") twins occur in 33.3 per 1,000 US births. What are the odds of twins marrying twins and having twins? Consult your bookie.