Oral sex, often called fellatio when performed on a penis and cunnilingus when performed on a vulva, is sexual activity involving the stimulation of the genitalia of a person by another person using the mouth (including the lips, tongue, or teeth) and the throat. It is sometimes called oral intercourse.
Facesitting, also sometimes known as queening or kinging depending on the gender of the person doing the sitting, is a sexual practice in which one partner sits on or over the other’s face, for the sake of oral sex or anilingus.
Some sexually transmitted infections (STIs), such as chlamydia and human papillomavirus (HPV), can be transmitted through oral sex. Any sexual exchange of bodily fluids with a person infected with HIV, the virus that causes AIDS, poses a risk of infection. Therefore, using a condom (for a penis) or a dental dam (for a vulva) is recommended if you are not sure your partner has no STIs, or know they have one or more. Risk of STI infection, however, is generally considered significantly lower for oral sex than for vaginal or anal sex, with HIV transmission considered the lowest risk with regard to oral sex.
A table in Larry Townsend’s The Leatherman’s Handbook II (the 1983 second edition; the 1972 first edition did not include this list) which is generally considered authoritative states that a light blue handkerchief is a symbol for oral sex in the handkerchief code. As well, placing a hanky in the left pocket indicates the wearer’s alignment with a top/dominant role, while a hanky in the right pocket indicates the wearer’s alignment with a bottom/submissive role. Townsend noted that discussion with a prospective partner is still important because people may wear a given color “only because the idea of the hankie turns them on” or “may not even know what it means”.