A quickie is a brief act of sexual intercourse. People will not usually have much foreplay with a quickie.
A quickie may not always mean sexual intercourse. It may be oral sex or mutual masturbation. According to some, a quickie between a heterosexual couple generally satisfies only the man. Others claim that quickies (with intercourse or some other form of stimulation of the vulva) can also be "a major turn-on" for a woman. Since it may not give a woman enough time to lubricate naturally, she might need a lubricant. Some consider quickies a solution to unequal sexual desire in a relationship. If they become the only form of sex, the relationship may suffer. For gay men, a quickie sometimes means casual sex, like a hand job. It does not usually happen with lesbians, however.