Edge: Playing with yourself up to the point of orgasm then stopping. No orgasm takes place.
Ruined Orgasm: Masturbation until the point of orgasm then 'hands off' so the cum dribbles out.
Tucked: Testicles tucked up into their pockets and penis pulled back throu the legs.
Nub/Nubbed: Rubbing a tucked penis to the point of orgasm so the cum drips over the anus.