Objections to Fellatio
Some people are uncomfortable performing fellatio because they have a sensation of gagging when they take the erect penis into their mouth. This real physiological event, known as the gag reflex, is triggered by pressure at the back of the tongue or in the throat. If a man, in his excited state, pushes his penis too far into his partner's mouth, the gag reflex may take over. One way to avoid this problem is for the person giving the oral sex to grasp the penis along the shaft to control how much of it enters the mouth.

Another common objection to fellatio is having the man ejaculate in his partner's mouth. A couple can agree in advance to have the man remove his penis from his partner's mouth before ejaculation. Others don't mind. They either rinse the ejaculate from their mouth right away or they swallow it. The ejaculate, on average about 4 cc, consists of proteins and sugars and reportedly contains less than 36 calories.

Cunnilingus, like fellatio, can be performed in many ways. Women's preferences vary, but commonly enjoyed techniques include gentle tongue movements over the clitoris, more rapid, focused licking, or sucking the clitoris either gently or in a rougher fashion.

Other forms that women enjoy are oral stimulation of the clitoris combined with fingering of the vagina; licking and kissing of the lips just outside the vagina; having the tongue thrust in and out of the vaginal opening; and having the clitoris stimulated by hand (her own or her partner's) while oral stimulation is directed at other parts of the genitals.

Reservations About Oral Sex
Not everyone has or enjoys oral sex. Many people who try it enjoy oral sex, but others have reservations about it. These reservations tend to fall into three arenas: first, that oral sex is unhygienic; second, that there is a taboo against it; third, that it is not a true expression of femininity or masculinity.

With regard to hygiene, neither vaginal fluid nor semen is harmful in any way. This of course is true only in persons who are not infected with a sexually transmitted disease (STD). Everyone should be sure that they themselves and their partners are free from STDs before engaging in any sexual activity.

No disease can be passed by oral sex that wouldn't be transmitted by any other kind of sex. If one partner has a STD the other is likely to catch it whatever they do together sexually.