I'm Proud to Be a Substitute, but I Know My Sister's Waist Is Weak

[Sister-Brother Love] [The dank puppy who pretends to be good on the surface vs. The bright and sexy beauty who cannot forget the old love] When Mu Wanzhou was twenty-two years old, Shen Shiyu was a sixteen-year-old kid. He hadn't grown taller yet, he was dark and thin, but like a little adult, he took the wine glass from Mu Wanzhou's hand, frowned, and told her seriously, "Sister, drink less wine, it's not good for your health." When Mu Wanzhou was twenty-six years old, Shen Shiyu was already a veteran who could drink a thousand cups without getting drunk. He held Mu Wanzhou's hands and pressed against her forehead. In the fireworks of the summer night, his eyes flashed with unclear emotions. "Sister, after all these years, your drinking ability has not improved at all? Tell me, how are you going to compensate me if you lose?" Seeing the similar facial features to that person's, Mu Wanzhou couldn't help but step up and kiss him. When she woke up the next day, Mu Wanzhou looked at the other side of the bed, where her eight-pack abs were hanging out. She swallowed, put on her clothes and prepared to run away, but a pair of big hands snatched her back. The little wolfdog, who was still looking fierce at night, now has wet eyes open and holds Mu Wanzhou's waist tightly, "Sister, I drink too much and I feel uncomfortable. How about you rub it for me?" Mu Wanzhou's face turned red instantly, "Rub... Where?" [Summary in one sentence: I am proud to be a substitute, and I know how weak my sister's waist is~] [PS: Underage people are not allowed to fall in love. They will have a crush. If you want to talk to your sister, you must be an adult first]