How To Use My Sister Got Parties I Got A Spreadsheet For Planning?

On the night of my sister’s engagement party, my life officially crashes. Again. All because of one name on the invitation. Zachary de Sanctis. My sister’s fiancé. Fiona. My ex, the guy I punched in the face five years ago. Heir to the richest old-money family in Europe. And one tiny detail only God and I know: he’s the father of my twins. For the past five years, I’ve been hiding out in a little town in Oregon, working as the CEO of a IT firm while chasing two four-year-olds who look more like their father than me. Isaac and Isabella: two mini De Sanctis clones with the last name Gómez, razor-sharp mouths, brains that run too fast, and a talent for causing trouble exactly when I need peace. My family knows I came home pregnant and alone. They just never asked who the father is, and I never offered an answer. As far as they’re concerned, I’m still Arabella Gómez, the wild one who lost her way. I thought going to Fiona’s engagement party would just mean a few hours of fake laughing, then a quiet drive back to my glass-walled house in Oregon and two sets of blue eyes calling me Mommy. Until Zach walks into my parents’ living room holding Fiona’s hand… and his gaze stays on my face a little too long. He can’t find out about Isaac and Isabella. Fiona can’t find out her perfect fiancé was mine first. And my family can’t know what really happened five years ago. Hiding a scandal between two rich dynasties is one thing. Hiding two chaotic twins who are basically their father’s face copy-pasted? That’s the real nightmare.

Right after I get accepted to my rich biological family, I become my older sister, Josie Sonnenfeld's marriage replacement. In the first marriage alliance, Josie despises the fact that her partner, Zane Lowry, is a hedonistic playboy who can't even hold down a job. On the day of their engagement, she's fled all the way to another country with another man. I pin Zane down and teaches him how to cook up a perfect scheme so that he can overtake his arrogant half-brother who happens to be a bastard son. In the second marriage alliance, Josie looks down on Benjamin Shaw, a low-income college student who comes from an ordinary family. On their wedding day, she makes sure to humiliate him in front of everyone before ditching him at the altar. With the money I've saved up, I spend one long, grueling year in the basement with Benjamin as he works hard to establish his success. I'm with him until the day he becomes the director of the National Research Institute. In the third marriage alliance, Josie scowls in disgust when she realizes Rowan Gallagher is a total momma's boy. She wastes no time traveling to a tropical island with her male best friend afterward. As for me, I walk into the stressful-looking manor and drag the cowardly Rowan out. By the time I'm done reshaping him, he has succeeded in taking over every single business belonging to his family. Three years later, Josie, who has spent every single cent overseas, has no choice but to return to the country while heavily pregnant. "Thanks for watching over these losers in my stead, Laura. Now that I'm back, you can get lost now." Josie intends to pick one out of her three ex-fiances to become her unborn baby's father. Meanwhile, I tap on a group chat titled "Happy Family" and sends a text there. "Josie is back for you three." Everyone in the group chat instantly goes haywire. The men are quick to proclaim their love and loyalty toward me. "Don't worry, honey! Our hearts and bodies are yours!"

My mom calls me on Friday. "Don't forget about tomorrow's family dinner. Cody loves shrimps, so you should buy more of those at the seafood market in the southern district. "Lexi loves lamb chops. Go take a look in the eastern district for them. Also, don't forget to buy the imported strawberries. Noah loves them a lot." I say yes to each and every request Mom makes. But as soon as I end the call, I receive a text on the family group chat. "I've already given Eileen a list of our favorite foods. It's tough for you to earn money these days, so you shouldn't buy anything." One second later, that message is deleted. Still, I'm flabbergasted by what I just read. I've been married for two years. Every Saturday throughout those years, I'm the one paying and organizing the family dinner of the week. I thought there's no need to be so petty when it comes to family. But it seems that they've already viewed me as the outsider a long time ago. In that case, I won't be attending the family dinner anymore.

I failed my college entrance examination. My father decided to sell me to the village chief’s hot-tempered, crippled son. My younger twin sister helped me escape in the middle of the night. It was only later that I discovered my younger sister was the one who had failed the examination. She used my identity to attend college and hooked up with a rich heir. At her engagement banquet, they revealed the truth that she had taken my identity. As a result, the event fell apart. Out of rage, my sister pushed me down the stairs. I grabbed her and pulled her down with me. When I opened my eyes again, I returned to the day the examination results came out.

My sister, Luna Rivers, is famous in Bridgeburg for being absurdly devoted to her little brother. She spends millions of dollars to throw a party for my 18th birthday. But on the day of the party, she personally locks me inside a small dark room. By the time I smash the door open and stagger into the ballroom, covered in blood from head to toe, she is gently holding another man's hand as they cut the birthday cake that should be mine. That man looks exactly like me. Even the scar on his wrist is identical to mine. I barely take a step forward to demand an explanation when a flood of messages suddenly explode across my vision. "The male supporting character is hilarious. He's just an adopted stand-in. Why's he getting jealous of the main character?" "Just wait. Later, he goes completely insane trying to compete for affection. The female lead will break his arms and legs, then have him admitted to a mental hospital. Serves him right!" The blood in my veins turns to ice. Luna spots me. Her first reaction is to shield the man protectively behind her. Then she snaps coldly, "Don't make a scene. Jeremy is my real brother. I'll explain everything later." Jeremy? We have the same name and the same scar. I really am the perfect replacement.

She has always lived in the shadow of her perfect, caring sister until one night changes everything. At her sister’s engagement party, what should have been a normal, graceful evening turns into something she can’t fully understand. A blurred vision. A stranger. A mistake she wishes she could forget. But the truth refuses to stay hidden. The man from that night is her sister’s fiancé. Now trapped in a secret that could destroy everything, she’s forced to question what really happened and why it feels like more than just an accident. As memories slowly return, one thing becomes clear—this was no ordinary mistake. And the deeper she digs, the more dangerous the truth becomes.