Robots will be more and more present in our daily life. Even if we guess that they will help us doing our tasks, their future roles remain unclear. Thus, it is important to explore how robots implicitly influence people, in order to design their future roles. This paper investigates human's behaviors in three game conditions: game with a robot alone, a tablet alone, and both robot and tablet. Results show that the presence of the robot induces no stress. Participants feel more pleasure when they play with the robot alone. Results also highlight that interacting simultaneously with a tablet and a robot could be experienced as a negative situation by people.