The wedding crasher is one that they, or their invited guests, will never forget.
Jason and Kate Crowe tied the knot in Saint Croix.
Soon after their vows were said, a giant leatherback sea turtle emerged from the water to lay its eggs.
The Crowe's said the wedding party kept a safe distance, but did not miss out on the surprise photo op.
"Of course from Pennsylvania, you don't expect to see a turtle as big as a Volkswagen," said Jason.
The couple has now taken a special interest in the endangered species.
They've joked about going back to St. Croix in 60 days when the eggs hatch.