Dry fuck is not the same thing as dry hump. Dry fuck is the result of a girl skipping foreplay and cutting straight to the intercourse without being in the mood. Her pussy is not as wet as it would be otherwise, so therefore the intercourse was just a 'dry fuck.'
When the hooker saw what a fat slob John was, she decided to speed up her for work and just dry fuck John.
when both a man and a woman simulate sexual intercourse by rubbing their genitals against each other with friction but without actual penetration. Usually done through embracing with each partner between the other partners legs. Very erotic when both genitals are clothed.