The Whip of Domination is crafted from a severed vine (only one available, dropped by the vine boss) and a potion of virility. It is equip-able / wieldable which works just like clothing. If it is cursed you will not be able to remove it from your hand.
The whip modifies your slap damage based on its BUC and magic modifier. It also gives a damage bonus / reduction based on your submissive sex addiction, the more dominant you are the higher the bonus, the more submissive you are the more the reduction. The whip also gives a bit of bonus damage if you are currently very horny (but being horny lowers dexterity so this might not be desirable overall in some fights).
Wielding the whip makes you able to become horny even if your sex addiction is currently low. Attacking with the whip will arouse you if you are not yet fully horny. You cannot perform a normal slapping attack whilst wielding the whip and damage modifiers such as the reduction from having very large breasts will still apply.
Killing a monster with the whip lowers sex addiction and humiliation.