Vanilla sex is a term that refers to standard or normal sex. Different cultures, subcultures, and individuals have different ideas about what constitutes vanilla sex. Often it is interpreted as sex that does not involve such elements as BDSM, kink, or fetish activities. Among homosexual men it sometimes implies that the activity is non-insertive (i.e. interfemoral intercourse, manual stimulation, frottage etc.)

The term 'vanilla' derives from the use of vanilla extract as the most popular flavoring for ice cream, and by extension meaning 'plain' or 'conventional'.

Neapolitan is a term proposed to describe the sex life of a person that enjoys "vanilla sex" (the commonest, and thus "default", flavour of ice cream is vanilla) as well as other "flavors" of sex, such as BDSM.

The term is presumably coined in reference to Neapolitan ice cream, which has layers of different colours, including a layer of vanilla flavour, rather than the inhabitants of Naples.