tiny melon

Had some volunteer cantaloupe in the garden this year, also a few cucumber plants. I kind of forgot they were there, and never went searching for fruit under the broad leaves until it was too late. Most of the fruit rotted. This one was still good, although very small. It looks like a tiny cantaloupe.

The inside was green. I thought just not ripe- but it tasted exactly like a cucumber. Better than the actual cucumbers I got. I think the two melons crossed?