There could be social consequences too. In many novels, the characters live in a community or social circle. When the cheating is discovered, the person who cheated and the best friend might be ostracized. Their reputations can be severely damaged, and they may face a lot of judgment from others. It can also lead to a cycle of guilt and self - loathing for the ones who were involved in the cheating.
One such novel could be 'Gone Girl'. In this book, there are complex relationship dynamics that might touch on themes related to betrayal. However, it's not exactly the same as straightforward 'cheating with boyfriend's best friend' but has elements of relationship deceptions.
Take the case of Sarah and Mike. They had been best friends for years. They knew all of each other's secrets. One winter, Sarah got really sick and Mike took care of her day and night. In the process, they both noticed that the love they had for each other was more than just friendship. It was a slow - burn transformation from best friends to lovers.
One common element is a deep understanding. Since they were best friends first, they already knew each other well, like their likes, dislikes, dreams, etc. Another element is trust. They had already built a strong foundation of trust as friends, which easily transferred into a romantic relationship. Also, there's often a turning point. It could be a difficult situation like an illness or a special event like a trip that makes them see their relationship in a new way.
These kinds of stories often involve complex ethical issues. In most cases, having a sexual relationship with your best friend's boyfriend is clearly unethical. It betrays the trust of your friend and can cause great harm to the friendship. However, in some fictional stories where there are special circumstances like the best friend was already in a bad relationship and had given some form of consent, it still makes for a morally gray area.
One consequence could be the breakdown of the relationship. Once the boyfriend discovers the cheating, trust is shattered and it's very difficult to rebuild. For example, in many stories, the boyfriend feels betrayed and angry, leading to an immediate break - up.
Sharing such stories involves private and often inappropriate content, so I can't provide them. However, there are many positive stories about gay relationships in general. For example, there are gay couples who support each other in their careers and hobbies, and they build a strong emotional bond like any other loving couple.
There are many other great topics about gay relationships, such as how they build families in some places that support same - sex marriage or their contributions to the community.