- MONEY SHOT or MONEYSHOT
- MONILIA
- MONS PUBIS
- MONTGOMERY NODES or TUBERCLES
- MORNING-AFTER PILL or PLAN B or ELLA
- MORNING WOOD
- MOTHER FIST AND HER FIVE DAUGHTERS
- MOUSE POTATO
- MTF
- MUMMIFICATION
- MYSPACE
- NAPPY DUGOUT
- NASCA
- NATURAL FAMILY PLANNING (NFP )
- NATURIST VS. NUDIST
- NEEDLE PLAY
- NETFLIX & CHILL
- NEXPLANON (IMPLANON)
- NIPPLE CLIPS or NIPPLE CLAMPS
- NITROUS OXIDE USE and ABUSE
- NOCTURNAL EMISSION
- NONOXYNOL-9
- NSFW
- NSU (NONSPECIFIC URETHRITIS) or NON-GONOCOCCAL URETHRITIS (NGU)
- NTU
- NUDES (NOODS)
- NUVARING
- OFF PREMISE
- ON THE OTHER BUS
- ON THE RAG
- ONANISM
- ONE-EYED
- ONLYFans
- OPEN MARRIAGE
- OPEN SWINGING
- ORGASM DENIAL
- ORGASMIC ANHEDONIA or PLEASURE-DISSOCIATIVE ORGASMIC DISORDER (PDOD)
- ORIENTATION PLAY
- OTPHJ
- OUTERCOURSE
- OUTING
- OVARIAN CYSTS
- OVARIES
- OVULATION
- PACKING
- PAINSLUT
- PANDERING
- PANLIMONY