Yes, there are. However, it's important to note that these might be misinterpretations. For example, in some cases of hazing or dares in a non - sexual context, actions could be misconstrued and then turned into such stories. But the idea of a straight guy engaging in such an act in a sexual sense may be more of a salacious rumor.
They can be considered a bit of both. In many cultures, such topics are considered taboo due to their sexual nature. However, from a personal experience perspective, some might see it as part of their sexual exploration journey. But it's important to note that these are very private and not something to be shared casually in all social settings.
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.
Most literature aims to promote positive social values, and topics like this are not part of the acceptable content in literary works. We should look for stories that are about love, friendship, and moral growth in literature.
I'm not aware of any such stories in mainstream popular culture. Truckers are usually associated with their driving jobs, long hauls, and the trucking industry in general, not such inappropriate or vulgar content.