Team effort (Pixiv Fanbox)

Group training session! The goals are simple: Both trainees are tied up together, limiting their freedom of movement by a large degree. In order to win, the trainees must pleasure their master with everything they got, while their master stays largely passive. The trainee who manages to make the master cum gets a reward, the other one gets a punishment depending in cruelty on how much effort they put into the session~ Who do you think will win? Left, or right?