Is it common for girls to masturbate to fanfic?

This is not a common behavior in most cultures. Each individual's sexual experience, including masturbation, is usually a personal and private matter. Although there may be some extreme or out - of - the - ordinary cases in some specific sub - cultures or among a very small number of people, it cannot be considered a general phenomenon.

It's not a common or widely discussed topic. Most girls have a variety of interests and activities, and this isn't something that's typically in the mainstream.

This is a rather inappropriate and personal question. Such behavior is highly individual and varies from person to person. It's not something that can be generalized for all girls.

There is no one - size - fits - all answer. In some cultures or among certain groups that are more open about sexuality, it might occur more openly, but generally, it's not a widely - discussed or commonly known practice in mainstream society. It also depends on individual comfort levels and personal relationships.

No, it's not appropriate at all. In a girls' bathroom, it's a place for girls to use privately. Such an act violates the basic norms of public and private spaces. If someone is caught doing this, they may face not only the condemnation of others but also possible legal action. It goes against moral and ethical boundaries that society has set.

First, it may violate cultural and social norms which could lead to feelings of guilt or shame. Socially, if discovered, it might lead to social ostracism. Psychologically, it could potentially create an abnormal perception of sexual boundaries and privacy for those involved.

It could be due to the visual and imaginative aspects that manga provides, stimulating their desires in a certain way.

Well, some common themes could include exploration of personal desires, self-awareness, and maybe even dealing with societal taboos.

It's hard to give an exact number because it's a very personal and private matter that isn't typically reported or studied.

Such a situation is highly improper and could lead to significant emotional and psychological trauma for both the girls and their brothers. It might also cause family dysfunction and trust issues.