I'm not entirely sure if there is a specific one. While fanfiction can cover a vast range of scenarios, including some that deviate from the expected character relationships. The idea of Arthur cheating on Merlin with Gwen seems rather untrue to the spirit of their relationships in the common Arthurian tales. But in the world of fanfiction, anything is possible.
Merlin might become even more protective of Arthur. Since Gwen is carrying Arthur's child, Merlin would see it as his duty to safeguard the future of Camelot. He could be more involved in Arthur's personal affairs, which might initially annoy Arthur but eventually he'd come to appreciate Merlin's concern.
One great fanfiction is 'The Once and Future King's Love'. It beautifully weaves the relationships between Merlin, Gwen, and Arthur. It shows their deep friendship and the budding romances in a really engaging way. The author does a wonderful job of staying true to the characters' personalities from the show.
Popular 'Merlin Arthur Gwen fanfiction' often has strong character development. It dives deep into the personalities of Merlin, Arthur, and Gwen, showing their growth and how they interact with each other. For example, it might show how Arthur becomes more accepting of magic because of Merlin and his relationship with Gwen.
One great 'Merlin Arthur Gwen fanfiction' is 'The Bonds of Camelot'. It beautifully weaves the relationships between the three characters. It shows how Merlin's magic subtly influences the dynamic between Arthur and Gwen. Another one is 'A Triangular Affair' which delves deep into the complex feelings they all share for each other in a really engaging way.
It would become much more complex. They might start off being confused and a bit awkward around each other. But then, as they start to explore their feelings, they could become closer in a more intimate way. Their friendship would be transformed into something deeper, with a new level of understanding and trust.
In a fanfiction, it could be that an evil sorcerer casts a spell on Gwen and Arthur's unborn baby. The baby starts to show strange and dangerous symptoms. Merlin is the only one who can sense what's really wrong. He has to race against time to break the spell. He delves deep into his magic knowledge and also consults ancient magical texts. Along the way, he has to hide his actions from those in Camelot who still distrust magic, all while trying to save the baby and ensure the future of Camelot's royal family.
The complex relationships. Merlin's loyalty to Arthur, his friendship with Gwen, and the love triangle between Arthur, Gwen and the unspoken feelings Merlin might have. It's all very interesting to explore in fanfiction.
One interesting story could be where Merlin uses his magic to secretly help Arthur court Gwen. For example, he might create small magical moments during their encounters, like making the flowers bloom around them at just the right time. Another could be a story where Gwen discovers Merlin's magic early on and they team up to protect Arthur from various threats.
There might be a fanfiction where Merlin uses his magic to create a special bond between Arthur and Gwen. This bond allows them to communicate telepathically, which helps them in battles and diplomatic situations. As they grow closer through this unique connection, they also face challenges from those who fear the unknown magic at work.
Merlin might be initially shocked and heartbroken. He has been so close to Arthur, and this sudden forgetfulness would be a huge blow to him.