My older sister is a serious person who doesn't know much about sex, but she was in a good mood today, so I asked her, "Has anything good happened?" Apparently, she had gotten her first boyfriend. - Eventually, she would start asking me questions about sex, so I played with her as I saw fit, but eventually her eyes changed and she started staring at my crotch while drooling, and she was going to imitate me and suck it in her mouth, so I decided to let her like it for now. - I tried it.