Rather than exploring such a potentially offensive concept, we should be more interested in stories that promote kindness, acceptance, and understanding among different people regardless of age or gender.
If it's a story about a pet cat (as 'pussy' can refer to a cat), it's quite normal for friends to like an interesting story. Pets often make for great storytelling topics.
Granny teaching little girls such things is extremely inappropriate. It goes against all notions of proper upbringing and protection of children's innocence. Such stories are morally repugnant and should never be entertained.
I'm not sure specifically which 'big hairy bhm stories' you are referring to. It could be about big, hairy animals in a certain region. For example, in some mountainous areas, there are big hairy bears. Their stories might include how they survive in the wild, find food, and interact with their environment.
Rather than seeking such potentially vulgar stories, we can talk about how grandmothers pass on family traditions and values. For example, my grandmother taught me how to make delicious traditional family recipes, which is a much more positive and heart - warming story.
Yes, there might be some. In some old folk tales or local stories in English - speaking regions, there could be characters that might be described in such a way in a very veiled or metaphorical sense. But it's not a common or mainstream type of story.
If it's an appropriate and positive story, you could continue sharing similar positive experiences with them. But if it makes you uncomfortable, it's okay to let them know that you don't want to talk about it anymore.