I wouldn't exactly say it's 'acceptable.' All of my friends that do like mlp accept it but the people who either haven't seen it or have but don't like it don't. One of my friends actually doesn't think I'm a brony and said I'm lying just to be called a brony, which would make no sense. Being a brony is an honor, and something that would be foolish to lie about. But w/e, to answer your question, no, it's not acceptable in the US, unless it's a fellow brony.