Merleau-Ponty wrote about the inherent reversibility of the hand shake: both hands, both bodies touch each other and are being touched at the same time. The movement is reversible; the bond that’s created is mutual.

This is true whenever I touch another person (except when I’m using an object to touch the other person). The reversibility of the movement- the fact that both of us touch and are being touched at the same time- is essential to the bond between us.

When I induce pain in another body through my touch- this bond is ruptured.The Other  now feels an intense stimulus that takes control over her or his attention. He or she feels something very strong. What I feel becomes close to nothing. The intensity of the pain the felt by the Other minimizes my own weaker and more mundane sensations. The movement is no longer reversible. The bond is ruptured.