Lama Ole’s answer:
The Buddha gave teachings for different people. He taught monks and nuns to consider physical sensations as something unpleasant since it is dangerous for them—for their peace of mind. He told lay people that the body is a way to give joy and a means through which to work with the mind. On the highest level, it is said that there are 72,000 energy channels in the body, all of them radiant, all of them meaningful. One sees the female part as a lotus flower and the male part as a diamond. One regards the whole body as a mandala, a power-field of light and energy.
If we practice on the Diamond Way level and consider the body impure, then we are breaking our bonds. If we experience somebody else’s body as unpleasant, repulsive, impure, or meaningless, we are stepping out of the buddhas’ power-field.
I have no idea how the monks work with this; maybe they keep it disconnected in their minds. But if one practices on the level of the Diamond Way, if one has received teachings on Mahamudra and then considers the body as something impure, then one actually throws everything away again. I always tell my students that highest truth is highest joy, and one should hold this level as well as one can.