Some people complain that the thickness of the plastic dulls sensation.
A report issued in September 2005 by the National Center for Health Statistics was the basis of an article in the September 26, 2005 issue of Time magazine.
Recognizing that some of the studies potentially included the presence of confounding factors, such as the possibility that women who regularly perform fellatio and swallow semen also engage in more frequent intercourse, the researchers also noted that, either way, "the data still overwhelmingly supports the main theory" behind all their studies—that repeated exposure to semen establishes the maternal immunological tolerance necessary for a safe and successful pregnancy.
Laws of some jurisdictions regard oral sex as penetrative sex for the purposes of sexual offenses with regard to the act, but most countries do not have laws which ban the practice itself, in contrast to anal sex or extramarital sex.
Oral sex is not necessarily an effective method of preventing sexually transmitted infections (STIs), although some forms of STIs are believed to be less commonly spread in this way, and oral sex has been recommended as a form of safe sex.
but using a real dental dam is seen as preferable; this is because real dental dams cover a larger area, avoid accidents caused by "slipping" outside the covered area, and avoid the risk that makeshift versions may be accidentally damaged or poked with the scissors during the cutting procedure.
For conception to take place, sperm from the penis must enter the uterus and fallopian tubes and fertilize the female's egg.
In humans, there is no connection between the gastrointestinal system and the reproductive system, and sperm ingested by the woman would be killed and broken down by acids in her stomach and proteins in the small intestine.
The study concludes that people who had one to five oral sex partners in their lifetime had approximately a doubled risk of throat cancer compared with those who never engaged in this activity and those with more than five oral sex partners had a 250 percent increased risk.
Facesitting is a form of oral sex in which the receiver sits on the giver's face and pushes into it with his or her genitals.
Oral sex can also be performed by both partners at the same time in the so-called "sixty-nine" position.
The Centers for Disease Control and Prevention (CDC) stated in 2009: "Studies indicate that oral sex is commonly practiced by sexually active male-female and same-gender couples of various ages, including adolescents." Any sexual exchange of bodily fluids with a person infected with HIV, the virus that causes AIDS, poses a risk of infection.
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.
An act of group sex restricted to one woman giving oral sex to several men is referred to as a gangsuck, blowbang or lineup, all derivatives of the slang term gang bang for group sex. Oral sex is commonly used as a means of preserving virginity, especially among heterosexual pairings; this is sometimes termed technical virginity (which additionally includes anal sex, mutual masturbation and other non-penetrative sex acts, but excludes penile-vaginal sex).