- SMEGMA
- SNAP-ON TOOL
- SNAPCHAT SEXTING
- SNATCHCHAT
- SNEAKY LINK
- SNOWBALLING
- SO
- SOAPY TIT WANK
- SODOMY
- SOFT SWINGERS
- SOUNDS
- SOUTHERN COMFORT
- SPANISH FLY
- SPASM CHASM
- SPECTATORING
- SPERMICIDE for birth control
- SPERMJACKING or SPURGLING (SPERM + BURGLING)
- SPIT ROASTING
- SPLASH CONCEPTION
- SPLIT BEAVER
- SPLOSHING
- SPONGE for Birth Control
- SPREADER BAR
- SQUIRTING
- SRPE or Sleep-Related Painful Erections
- SSC
- SSRIs
- STAR-TREK SEX
- STENDRA
- STFU
- STI or STD
- STONE BUTCH
- STONEWALL
- STRAP-ON
- STROKER
- STUNT BABE
- SUPERFICIAL DYSPAREUNIA
- SURFER
- SUS
- SWEET DEATH
- SWING LOW
- SWINGERS
- SWIPE RIGHT
- SWITCH
- TACO BLOCK(ING)
- TADALADIL (CIALIS)
- TAINT
- TAR BEACHES
- TEA-BAGGING
- TEDDY