Well, I don't have direct knowledge of a 'bowser x luigi mpreg fanfiction' being out there. However, the world of fanfiction is huge and diverse. Some fanfic writers love to explore unique and unexpected pairings and concepts. If you're really interested in finding it, you could also join some Mario - related fan communities or forums and ask around. Maybe someone there has come across such a story or could even point you to where to find it.
I'm not sure if there is specifically a 'bowser x luigi mpreg fanfiction' available. Fanfiction can cover a vast range of themes and pairings, but this particular one might be a bit of a niche or unusual concept. You could try searching on some major fanfiction websites like Archive of Our Own or FanFiction.net to see if it exists.
Chapter 548, "A Guy Named Gu Yu", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with No, we can't," Su Yinwan blurted out subconsciously.
Chapter 355, "She is My Only Sister", is the clearest early answer because it turns Mystical Skills's situation into a concrete plot event. Early on, Luo must have checked lots of news about me these past few days, so....
Chapter 368, "You Don't Deserve to Be My Mother", is the clearest early answer because it turns Du Qinglian's situation into a concrete plot event. The chapter gives readers a real answer by opening on I haven't detained anyone, how could I possibly detain him?
Chapter 539, "Aren't these the two who bullied Bai Lu before?!", is the clearest early answer because it turns Let's situation into a concrete plot event. The chapter turns that into something concrete by moving from On the other side of the jungle, Zhao Lang, who was trekking with all...
Chapter 468, "Joyously Receiving a Fainting Gift Pack", is the clearest early answer because it turns Zheng Xun's situation into a concrete plot event.
Chapter 730, "How Can You Make a Deal with a Madman?!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. It opens with Xu Ning's emotions grew more intense as she spoke.
Chapter 450, "Your dear brother is making breakfast for you!", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event. The chapter turns that into something concrete by moving from And as he fell, he understood why Lao San had screamed so miserably.
Chapter 398, "Have You Finally Decided to Use Gu on Your Family?", is the clearest early answer because it turns Use Gu's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Over the next month, Jiang Li drew up a detailed schedule— Up at 5:30...
Chapter 611, "The House She Built is No Ordinary House!", is the clearest early answer because it turns Ji Yanbai's situation into a concrete plot event. It opens with Jiang Li didn't care about the dissenting voices at all; she rolled...
Chapter 281, "Zhao Lang, Are You Willing to Take a Gamble?", is the clearest early answer because it turns Chen Xing's situation into a concrete plot event. Early on, In his dream, he found himself in a strange world..