Kafka was once again quoted during today's session at the Prague Writer' Festival: "Sex is the punishment for being in love."
See also here.
There are many things to be said about this, but perhaps we should first try to answer this question: why is being in love a crime or a misdemeanor? It's clear to me that we deserve punishment for love, but why exactly? Because we don't love enough or too much or because all love is self-love? Or because humans don't deserve love? We should learn to love goats.