No. Writing erotica stories that focus on such body parts in a vulgar way is inappropriate and goes against moral and ethical standards in most societies.
Well, in most stories, the 'Black Widow' is often a character with some sort of mystery or danger associated with her. But the 'big tits' part might be a rather vulgar or inappropriate addition to a normal story. In the context of real black widows (the spiders), there's no such inappropriate feature. In fictional stories that are more tasteful, the Black Widow could be a femme fatale - a dangerous and alluring female character, but not in the vulgar sense this title might wrongly imply.
We should focus on positive values. Instead of creating such vulgar content, we can write stories that emphasize respect, love and positive human qualities.
Another option is 'Lovely Tales of Moms'. By using this title, we are emphasizing the positive and endearing nature of stories that revolve around moms. It excludes any inappropriate content and presents a more family - friendly and positive image of mothers and the stories associated with them.
Maybe 'Mysteries of the Old House'. It creates an air of intrigue and can be used to tell a story full of secrets, perhaps about a family's history or hidden treasures in an old house. This is a much more appropriate and engaging title compared to the inappropriate one.
I'm not sure specifically what the 'fat black widow story' is without more context. It could be about a large black widow spider, perhaps a story regarding an encounter with one or some unique characteristic related to it.