Sister keeps brother focused - Part 4

The guy says that he's very ambitious and very obsessed about being the best at gymnastics. He spends 10 to 12 hours a day practising and all the family lives to help him to achieve his goal. He says that he doesn't have time to socialize, to go out with friends or even try to have a girlfriend so to release his sexual needs he depends on his sister. The best part is that their parents know about it and think it's good so he will stay focused on his only objective.