My Girlfriend Broke up with Me and I Became Her Brother-In-Law

The front foot just broke up with his girlfriend, and the back foot inexplicably took someone else's first blood. Coincidentally, the whole person is actually a childhood friend. What's even more coincidental is that his childhood sweetheart is actually his ex-girlfriend's sister? I have grown older for no reason, where can I reason... One day after that, his ex-girlfriend found Jiang Yufeng crying. Lin Mengrou: "Jiang Yufeng, it was my fault in the first place. Can we get back together?" Jiang Yufeng: "Sorry, I already have a wife." Lin Muxi: "Lin Mengrou, remember to call me brother-in-law next time. Do you still want me to teach you such a simple thing?" Lin Mengrou: "…………" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.