Vibrator (device designed to stimulate a woman's genitals).
Back-of-the-book; denoting those stamps in a catalogue that are not used for the payment of regular postage fees, and are displayed separately in the catalogue after that listing; the division between these two groups varies with the publisher.
Amorous behaviour, smooching, making out, necking, sexual intercourse or other sexual activity, especially if illicit.
Mischievous behaviour, dishonest or shady activity.
A debaucherous act; a sexual act that is considered inappropriate.