I suppose it's possible to spread a fungus or similar by touching one then another plant. I was told as a child that one should never go into or touch anything in the garden until the dew had dried. I always wondered why the cat was never chastised. cora

Watermelon plants don't seem to collect dew too much. I have also seen a bad female blossom that I haven't seen or touched before.

Any other comments/suggestions?

I would guess blossom end rot. I notice that many plants seem to grow out of the problem but with my pumpkins, the first few fruit tend to fail. Perhaps too much nitrogen rich fertilizer made the plant grow too fast for it's ability to move calcium. The egg shells will help but they are a very long term solution so they will probably not help this particular plant much, the milk spray will hopefully help more and perhaps a little liquid fertilizer around the roots that is high in soluble calcium.

I'm used to seeing many plants loose a few fruit to BER. So long as I manage to get my share of the fruit, I don't stress too much about it.

All the immature female flower buds that died of course haven't opened up/bloomed.
I guess I will continue with the milk spray and maybe pour a little diluted milk on the roots if the soil is dry enough.

I will also try to stop touching the new growth!
With some of the immature female flower buds that died, when I picked them off, I noticed I heard a air bubble pop or something when I squeezed the dead (immature) female flower bud to see if anything was inside it, or if it was all dried out. These ones must have been dead for a longer time, I would guess, as nothing came out of them, either.

From UF :

" Blossom-end Rot (Calcium Deficiency)
Symptoms: The blossom end of the fruit turns pale green to brown to black. These affected areas enlarge into sunken spots. The discolored fruit portion will shrivel into a dry rot unless the tissue is invaded by secondary organisms which often extend the area of rot throughout the fruit.

This condition can result from a number of situations that limit available calcium to the plant. Poorly limed soils may suffer from a deficiency of calcium in the soil. Calcareous soils seldom have this problem. Dry soil can limit calcium availability to roots regardless of the amount of calcium present in the soil. Fluctuations in between wet and dry soil conditions, even for short time periods, can result in deficiency symptoms.

Cultural Controls: Follow a program of soil testing and lime according to the soil test results. Supplement erratic rainfall with irrigation during fruit development to avoid blossom-end root development. Foliar application of calcium may help existing blossom-end rot problems."