Paizuri where neither of the participants use their hands or arms to touch the breasts.
Stimulation is generally achieved either by the receiving partner moving their entire torso in order to cause their breasts to bounce on the penis (e.g. post #5481154), or by the penetrating partner thrusting their hips into the breasts (e.g. post #4016158).
Contrast this with the more common type of paizuri where the breasts are guided or held still by one of the participants grabbing them.