Kabbazah Sex: tantric sex, male passive, female active
Kainotophilia: getting pleasure from change
Kakorrhaphiophilia: arousal from failure
Kalopsia: condition where things appear more beautiful than they really are (e.g. when you have been drinking)
Karezza Sex: coitus reservatus
Kegel exercises: exercises done to increase strength of the pelvic floor muscle.
Kenophilia: attraction to empty or open spaces
Keraunophilia: turned on by thunder and lightning
kickin': wonderful, great
Kicks: sexual thrills
Kinesophilia: arousal from movement and exercise
Kinky: sexual activity that is somehow non-traditional or exotic
Kleptomania: compulsion to steal
Kleptophilia: arousal from stealing
Klismaphilia: arousal from enemas
knickers or knicks: panties (British)
Knismolagnia: arousal from tickling
Knissophilia: attraction to incense-burning
Kokigami: the wrapping of the penis in a paper costume
Kolpeuryntomania: stretching of the vagina
Kopophilia: arousal from physical or mental exhaustion