Femoral intercourse can most aptly be described as "Sex, but not really." Femoral intercourse between a male/female couple occurs when the penis does not go into the vagina. Rather, as an alternative, the woman holds the penis lengthwise between her labia, like lying a pencil in the binding part of an open book or a hot dog placed in a bun. The woman can then use the penis to masturbate with, especially by rubbing her clitoris back and forth over the ridge where the head of the penis attaches to the shaft (called the frenulum). I'm guessing this is the main thing going on when many couples and teenagers practice the age-old art of "dry humping."