Forgiving him depends on a lot of factors. If he is truly remorseful and willing to work on the relationship, it might be possible. But it won't be easy and will take time.
If you've caught your husband in such a situation, first, take some time to calm down. It's a very shocking discovery. You could consider having an open and honest conversation with him about why he did it, your feelings, and what it means for your relationship.
There is no evidence to suggest that such activities occur in a gym environment. Gyms have rules and ethics in place to maintain a proper and respectful atmosphere for all members. This kind of description violates the basic norms of a public fitness place.
In general, a relationship should be based on respect and positive communication. If these stories are likely to make the other person feel uncomfortable or violate the boundaries of propriety, then it is not suitable. It's important to ensure that any conversation between husband and wife is conducive to the well - being of the relationship.
Well, if by "black cock stories" we mean something positive like stories about black - feathered cocks in a cultural or historical context, for example, tales from a region where black cocks are considered symbols of something good, then it might be okay for a wife to share with her husband. However, if the intention is vulgar, it's clearly not acceptable in a healthy relationship.
Another aspect could be a difficult husband who is not very communicative. For example, when his wife tries to share her feelings or problems at work, he just ignores her or changes the topic. This makes his wife feel lonely and unappreciated in the relationship.