I'm truly sorry to say this, but I don't think your friend is being genuine with you, and if they simply have fictives because they think they are hot or cute, that absolutely disgusts me. Because alters are living inside you, it's gross to think of someone who has no choice but to live with you in a way like that, because they don't have a say in what they can do, or to get away from it. While fictives do exist, and systems made of pure fictives also exist, this situation it just seems there's no way your friend is telling the truth.