Immoral or socially unacceptable sexual behavior is porneia. Something that society considers to be 'illicit', could be considered perfectly normal by others. e.g. Some would consider gay or lesbian sexual activities to be wrong and form of porneia. Others strongly disagree. The definition of 'normal' sexual behavior is a judgement based on popular opinion.
Porneia is not allowed and is against the rules of the Jehovah's Witness religion. Even flirting is not allowed.
Porneia involves 'immoral use of the genitals, whether in a natural or in a perverted way'. This includes oral sex, anal sex, and manipulation of the genitals between individuals who are not married to each other. Porneia does not require skin contact, copulation, or sexual climax. (Iv p. 99; w06 7/15 pp. 29-30; w04 2/ 1 . wOO 11/1 p. 8 par. 6; w83 6/1 pp. 23-26) Sept 2010 publication for Elders, "Shepherd The Flock Of God." 1 Peter 5:2 p.59