[Montaigne]:

:...we drip with sweat, we tremble, we turn pale and turn red at the blows of our imagination; reclining in our feather beds we feel our bodies agitated by their impact, some to the point of expiring. And boiling youth, fast asleep, grows so hot in the harness that in dreams it satisfies its amorous desires:

:     So that as it were an actual affair, / They pour out mighty streams, and stain the clothes they wear (Lucretius)