Thanks for the input. You are given a choice whether you want your dick to go or not. Depending on your choice, the story will branch in different ways. You can be a self-sacrificing hero and protect your brother or put yourself first and abandon him (how much you abandon him will have its own branching choices). If you choose to be a self-sacrificing hero you will be unable to have any sort of real sexual intercourse with any of the girls in the future, except just pleasuring them alone. If you put yourself first and you let your brother suffer the consequences, you'll be able to make relationships and bonds freely.
I really wanted to put a very serious choice to make early in the game, which will define the kind of character you are going to play as. If you guys don't want to have your dick chopped off (as is the normal thing to want), you can just select your brother instead. Your relationship will be damaged a lot, but it can be saved in the future (if you want to save it that is). But, disclaimer, if you do select your brother to pass through castration instead of you, you won't be able to get the "hero" ending. There are multiple endings written out for the story, but if you want to be the goody-two-shoes who always puts himself back, you'll have to sacrifice your dick lol. That doesn't mean there aren't other "good" endings if you want to keep your dick btw.