Hybrid seeds in my Nikita's Gift persimmons

I just ate a Nikita's Gift persimmon that had two seeds. I've never found a seed in them before, but I've only eaten about ten. I suspect it was pollinated by one of the American persimmon trees that are around 100 yards away. I like the flavor of American persimmons better, but huge size and usually no seeds make Nikita's pretty good. A back cross with an American would be interesting.  Could these seeds be fertile?

The seeds are a little flatter than Americans but bigger. They seem hard and fully developed.