- SADOMASOCHISM
- SAFE WORD or SAFECALL
- SAME-ROOM SEX
- SANGER, MARGARET
- SAPPHO
- SAUSAGE FEST
- SAVAGE, DAN
- SCABIES
- SCAT
- SCHLONG
- SCISSORING
- SCROTUM
- SCUMBAG
- SECONDARY ORGASMIC DYSFUNCTION
- SEMEN
- SEMEN ALLERGY
- SEMINAL VESICLES
- SEND NUDES
- SERIAL MONOGAMY
- SERODISCORDANT
- SEX BEFORE THE GAME
- SEX DREAMS
- SEX-ON-THE-BEACH
- SEX WORKER
- SEXILED
- SEXTASY
- SEXTING
- SEXUAL ORIENTATION
- SEXUALLY TRANSMITTED INFECTION (STI) or SEXUALLY TRANSMITTED DISEASE (STD)
- SHAGADELIC
- SHAKE ’N’ BAKE
- SHE-MALE or SHEMALE
- SHIBARI
- SHOCK DOC
- SHORT-ARM INSPECTION
- SHORT HAIRS
- SHOT MY WAD
- SHOWERHEAD EFFECT
- SIMP or SIMPING
- SISTERS OF PERPETUAL INDULGENCE
- SITUATIONSHIP
- SIXTY-NINE (69)
- SIZE QUEEN
- SKEET
- SKIN FLICK
- SKYLA
- SKYPE SEX
- SLASH
- SLOPPY SECONDS
- SLUT SHAMING