A/N: I know, a story about Annabeth cheating on Percy, not exactly original. I just hope that it being her perspective, and being about her regret over it will be an original enough twist to the cliche to make it readable.
She hadn't expected him to come back to camp a day early to surprise her. She especially hadn't expected him to come barging into her cabin looking for her. She had expected the chance to talk to him about it before she broke things up (betrayal's more like it) with him. She had planned to do it civilly, not like some ordinary whore.
When he found her, she left him there (more like fled from him) to deal with the fallout about the other boy alone. She didn't even really know the demigod that she had brought to her empty cabin (slut), but she had been feeling so lonely. Percy had been in New York, finishing his senior year of high school; away from her for the majority of the past nine months.
It's not like she hadn't wanted to leave to join him. Too many monsters hung around to constantly for her. She tried to tell herself that more powerful demigods, Thalia, Nico, and even Percy, were not only living, but thriving out there (weak). The thing was, she was used to the security of camp, growing up there from the age of seven. As much as they all trained in combat, and all the practice of the Second Titanomachy had given her, she had learned to be happy within the magical borders of Camp Half-Blood.
She soon found her at the Big House. She needed someone to talk to, someone to give her guidance. Maybe Chiron was there and not busy, if not him, then Rachel.
"You called me, dear?" an almost velvet voice asked her from behind. Annabeth spun around real fast, and saw Aphrodite.
"No I didn't," she snapped. Mouthing off to a goddess wasn't the best thing to do, but she didn't need advice from an immortal bimbo, even if she was an Olympian.
"I thought you were supposed to be smart. And really?" the love replied.
"What could you do?"
"Goddess of love, remember? I can work to mend your relationship. All I will need is to mark you."
"What is it?"
"Just a simple mark upon your breast. Will you accept?"
Annabeth thought for a moment before answering the deity. She decided: "Yes." The goddess touched the young woman's breast. Annabeth gasped, feeling a searing heat like fire upon it. And when the goddess lifted her hand, there was a scarlet scar in the shape of a swan, never to fade.
A/N: I'm reading The Scarlet Letter right now, and that book is as much an influence, if not more so, than all the stories with Annabeth cheating on Percy in deciding to write this.