Maybe not a fit for the humor thread, but seedless watermelons are hybrids that are grown from seeds. They are triploids, so they're sterile, and don't have their own seeds. But the seeds for them are produced by hybridization.
The common analogy is breeding a horse and donkey gets a mule, but then the mule is sterile. Seedless watermelons are sterile hybrids, so no seeds in them, even though they grow from seeds.