Hey Mel, I had that happen once with a pumpkin I thru in an open compost pile...
Had some wonderful pumpkins that year...
also, I left one water melon and one musk melon out over winter..
I didn't even see any reminence of watermelon...
it was just a tiny one and didn't think I'd get anything, but I got 3
seed sprouts..
And the muskmelon I saw a bunch of
seeds, but they weren't doing anything, so I thought, well,
I'll just bury them, I got 8 sprouts..
*of course the next day 3 were gone from slugs* but I'm keepin' my fingers crossed..
Keep us posted, would love to hear how they do!!!