Can't wait to see her finish him.

Being hit in the balls is not just site pain, it radiates into your abdomen, making you feel queasy or sick. It's a pain that sits inside you for a while, not like a muscle you can massage if you get hit there.

The erotic factor can go different ways for different people. The mainstream attitude is just getting off by being dominated by a woman. Some get off on feeling their genitals are worthless, and having someone treat them that way is validating that view. There can be a "call of the void" temptation to lose it all in some last erotic session that will end your manhood forever. Some enjoy being sissified - their maleness diminished and ridiculed.