Your Canteloupe is suffering the same as any fruit that holds a lot of moisture like Tomato's, etc, after the soil has been allowed to dry out, we are inclined to give the plants a good drink to compensate for the lack of moisture, this allows the plants to absolutely drink as much water as pos because they might be left high and dry again therefore, they drink to bursting point which I did earlier on this season with my Tomato's, Marrows, due to me being away for 2 days when the weather turned really hot for our climate.
Is there any way for future you could set up a soak hose that can water even amounts underground at the roots or into pots to allow a more even amount of water, MY friends have done this by using an old damaged hose pipe and they just used a punch to make even holes in the pipe they did lay it on top of the soil to test it was working and enough holes made, but to prevent evaporation they buried the hose at planting time.
Might be an idea for future, I know you can buy these drip water / feed hoses from garden centres but don't know the cost, they will last for years though.
Good luck. WeeNel.