My sister always bullies me and laughs at me. What should I do? My sister 15 19 I can't beat my sister. She is a black belt in Taekwondo.

Don't listen to their nonsense, it will teach you bad. Sister is a black belt, can't you try to be a black belt and be an "opponent" who can compete with her? Speaking of your sister bullying you, why don't you turn it into motivation and practice martial arts to beat your sister? Come on, come on. No matter what, you can't grab a girl's chest or lower body. One is the human body part, and the other is morality. If you do this, it will not only make your relationship with your sister strange, but also affect your daily life.