How I learned the truth about Lily and how it turned my world upside down is in the link in the comments.
When Luke, a 6-year-old boy, came back from school one day, he was overly excited to share with his mom that he had found his twin sister at school.
“Mom,” Luke started, “I swear…”
“What did we say about swearing?” his mom, Amy, asked him.
“Mom,” he continued, “I’m telling you, Luna is my twin sister!”
“Luke,” Amy responded with confusion, “You’re an only child, honey.”
“No, Mom! I’m serious. Luna and I have the same birthday, and we look alike. The teachers think that we’re twins, too,” the boy insisted.
For the rest of the day, he wouldn’t stop talking about Luna, her likes and dislikes, her favorite things, and more.
As Amy kept reassuring him that he was an only child and it wasn’t possible Luna to be his sister, Luke went to his room and grabbed the class photo. Amy had seen that photo before, but she didn’t pay attention to the rest of the kids.
When she saw Luna, she was a bit shocked. The resemblance between her and her son was uncanny.
Knowing there could be something behind this rather than a pure coincidence, Amy asked Luke if he wanted them to invite Luna and her mom over. Luke was over the moon.
“Do you think she’ll come?” Luke asked. “Like really come over?”
“I’ll speak to her mom tomorrow when I drop you off,” Amy smiled to her son.
When her husband Jeff returned home from work that night, Amy didn’t mention anything to his because it was too late and she had forgotten all about it.
The following morning, when she dropped Luke to school, Amy met with Luna’s mom, Penelope and the two arranged a playdate.
“Luna talks about Luke all the time, Amy,” Penelope said. “This will be great for them to spend time together outside of school.”
In the afternoon, Amy and Luke were waiting for his friend to come and baked some cookies. Jeff was home as well.
“What’s going on? We’re having people over?”
“Yes,” Amy said, but didn’t mention anything else.
Once at the door, Penelope and Luna were about to enter the place when Luna spotted Jeff and ran towards him, yelling, “Daddy!”
Jeff went pale and Luke said, “See, mom, I told you she was my sister.”
The room turned quiet as the three adults stared at one another.
“It was a long time ago, Amy,” Jeff started explaining. “Well, it was just before we found out that you were pregnant with Luke.”
Penelope stood quiet, it was obvious she knew Amy was Jeff’s wife when she agreed to take her daughter there.
“So, you knew?” Amy asked her husband. “The entire time, you knew?”
“I had to meet her,” Jeff said. “There was nothing else I could do.”
“I told Jeff to keep it a secret,” Penelope said. “I didn’t mind being a single mother to Luna, and my family helped me whenever I needed them.”
“I never meant for any of this to happen,” Jeff said then.
“Why would you put the kids in the same school?” Amy asked. “Did you really think that their paths were not going to cross?”
Then Penelope started to talk, “Jeff didn’t know about the school. I enrolled Luna in it recently, and anyway, Jeff knows the bare minimum about my daughter — it was what he wanted.”Amy needed the time to think. She was mad at Jeff, but she also needed to think of her son. Her trust was broken, but she agreed on couple’s therapy for the sake of her son.