There could be. Many fanfic communities have works centered around diverse sexual orientations for various characters. For Loras Tyrell, given his character in the source material, it's likely that some fans have created gay - themed fanfics. You might try searching in relevant fandom forums or groups to get more targeted results.
Common themes could include his place in society as a gay man. This might involve how he navigates the politics and social norms of his world while being true to himself. His relationships may also be a central theme, showing how they develop and grow over time. Additionally, themes of acceptance, both from himself and others, could be prevalent in these fanfics.
It could lead to a major shift in the power dynamics within the story. Cersei's and Loras' personalities and agendas might clash or combine in unexpected ways.
One good Loras fanfic could be 'Loras' Quest'. It delves into his character further, exploring his dreams and ambitions within the complex world of Westeros. It shows his growth from a young knight to a more politically aware figure.
One of the best qualities of Margaery Tyrell in fanfics is her intelligence. She is often depicted as very shrewd and able to navigate the complex political landscape of Westeros. For example, she knows how to use her charm and beauty to her advantage in the court.
Obviously, Loras Tyrell is a main character in most. In some fanfics, Margaery Tyrell also plays a significant role as his sister. They often have deep conversations about the family's political strategies. Another common character is Renly Baratheon, as Loras was his sworn shield. Their relationship is explored in detail in many fanfics.
It might mean a reshuffling of loyalties and alliances. For instance, Ned could influence Renly's decisions, or Renly's actions could save Ned from certain doom. The story could take on a whole new direction.
Another plot twist might be that the father of the baby is not who everyone thinks it is. It could be a secret lover, or perhaps there was some sort of magical interference that made it seem like someone else was the father. For example, if there are magical potions or spells in the fanfiction world, someone could have used one to deceive Margaery into thinking the wrong person was the father.
One common theme is the clash of cultures. Since Harry is from the wizarding world of Harry Potter and Margaery is from the political world of 'Game of Thrones', their different ways of life often collide. For instance, in many fanfictions, Margaery has to adjust to the use of magic which is completely new to her.