Something else I just thought about. The metaphor for splitting a watermelon is probably not the best fit because in real life, a watermelons weight would certainly be a float and not an int. Also, there's no real reason why anybody would need each half to be of an even weight, other than to fit the story.

Perhaps a better metaphor would make the problem easier to understand. For example, if the boys have a box of earplugs and want to make sure that they have the right number so that both boys can have earplugs for the future. In this scenario, the number of earplugs makes sense as an int instead of a float and there is a reasonable reason why each boy would need an even number since (most) people need 2 earplugs in order to function properly.

Just my thoughts.

I love an added story behind a problem, but this story was a bit verbose and obfuscates a fairly straight-forward task. It could easily be rewritten more concisely while maintaining the casual tone of the kata.

I can't even see anybody within my own clan. This is basically a must-have.