Face Sitting	:=	the top is "sitting" on the buttoms face. The details vary; some face-sitting is simply an expression of dominance; some is a part of breathing restriction games; some is explicitly sexual and the submissive is expected to perform cunnilingus/anilingus on the top.
Fellatio	:=	Cocksucking, giving a blow-job (BJ), going down on someone, being face fucked: the act of sucking or licking a penis, or having a penis inserted in the mouth. Once considered a perversion, now a common vanilla option, but also used among BDSMers. A bottom may perform fellatio as an act of submission.
Feminization	:=	For a man to be dressed and often made-up as a female, either voluntarily or under duress
Fetish	:=	An object that replaces people by objects as primary object of love; ex: Leather-, Leg-, Feet, Rubber-Fetish
Fisting	:=	Vaginal or even anal penetration using the fist/hand.
Flagellation	:=	Striking a person with an object
Flogger	:=	A multi strap/string whip, straps/strings are usually up to 20 inch long and made of leather or rubber
Foot fetish	:=	Podophilia := sexual arousal from feet (see also Fetish)