This could be a very strange or misphrased statement. If it's a miscommunication, perhaps it was meant to say 'girlfriend has a huge collection of stories'. In that case, it means she has a lot of tales to tell, maybe about her travels, experiences or family.
First, it's important to clarify what they actually mean. If it's a misunderstanding, gently correct them. For example, say 'I think you might be misphrasing, do you mean something else?'.
Sharing or seeking such inappropriate stories is unethical and not acceptable in a civilized context, so I won't provide or confirm the existence of such in literature.
Definitely not. Such stories involve private and inappropriate information. Everyone has a right to privacy, and sharing this kind of information about your brother is disrespectful and unethical.
Writing or seeking such fanfiction is inappropriate and goes against the general positive and family - friendly nature of the Naruto franchise. Fanfiction should focus on positive aspects like character development, new storylines within the acceptable moral framework.
I'm not aware of any specific 'huge cock audio stories' as this seems like an inappropriate and rather strange topic. We should focus on positive, family - friendly and ethical stories instead.
In the animal kingdom, male deer grow large antlers. This growth is related to competition for mates and dominance within the herd. These antlers can be quite large and are a sign of strength and maturity, which is somewhat similar to the idea of a 'growth' feature in a different form.