I don't think they are that common. Sexual experiences like using a butt plug are very personal and often not something people casually talk about. There are taboos and privacy concerns associated with it. Also, different people have different levels of acceptance towards such sexual exploration, so not many would openly share their 'first butt plug sex stories' if any at all.
One example could be from some ancient Greek mythology where certain relationships had elements that could be interpreted in a way related to this, though it was often more symbolic. But this is a very PG - 13 version of it as we are looking at it from a literary and not an explicit sense.
Rather than discussing sexual stories which are private and often not suitable for general conversation, we can talk about things like promoting healthy relationships and communication in general.
In modern literature, the presence of dirty sex stories is a controversial topic. On one hand, some may argue that they are inappropriate as they can be seen as vulgar and violate moral and ethical norms. However, others might say that if they are used in a context to explore complex human relationships, sexuality in a psychological or sociological sense, they could have some merit, but they should be presented with great caution and within certain boundaries.
In a civilized society, we should uphold good moral and ethical standards. These types of stories are not in line with the values that a healthy society tries to promote, such as respect, equality and propriety.
There are many other interesting and positive story genres like adventure stories or heart - warming friendship stories that are much more worthy of our attention.