I

Impotence
This is the inability to sustain an erection long enough, or hard enough to engage in sexual activity where penetration is involved. This doesn't mean you still can't have fun, and nowadays there are a variety of remedies. An orgasm still maybe possible with the right stimulation. If you have long term impotence is best to talk to a doctor about the underlying causes.

Infibulation
Sewing the foreskin over the penis or sewing the labia minora or labia majora of a woman's vagina (smaller and bigger lips respectively) together. This is sometimes done (if temporarily) in psychological sex games as a form of chastity over a partner. This is dangerous and not recommended, even if you're a medical practitioner!.

Insufflation
The act of blowing air into an orifice such as the vagina or anus. It is important to note that forcing a large amount of air into the anus or vagina may rupture a blood vessel. A bubble of air could also find it's way to the brain or heart causing instant death. But then if it feels good.

Inunction
Truly erotic massage! This is oiling up your lover, and then sliding over them using your own body or an object. The oil or lather provides a very different sensation from normal contact.

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Jactitation
We believe this is more common than anyone realises. Going out and bragging about sexual exploits that never occurred. Sometimes this leads to serious arousal.

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Kabazzah
This is a form of Tantra Sex where the male is passive and the female uses only her abdominal and vaginal muscles to stimulate the penis. It requires a great deal of self control (particularly from him!) but can lead to a whole new world in the bedroom. Or the kitchen. Or the living room. Or anywhere you please!

Kokigami
The Japanese art of wrapping a man's penis in a paper costume: Orgasmic origami anyone?

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Lactaphilia
The term used to describe someone who is fascinated to the point of arousal by breasts that seep milk (ie after childbirth).

Lap Dancing
Almost exclusively in specialist nightclubs and almost exclusively done by women for men, Lap Dancing is a dance where the performer will dance provocatively around (and on) the customer to sexy music for their arousal. In the UK men are not allowed to touch the dancer, although in some countries this is legal. A very successful way for women to relieve men of their money!

Lygerastia
A condition or fetish where you can only be sexually aroused in darkness.