Quickie is a slang term for a brief sexual encounter, usually one that takes place within time constraints. Quickies can be spontaneous or planned. It is important to note, however, that the term "quickie" is relative. What might be a short sexual encounter for some may be on the long side for others. One study of 500 (heterosexual) couples found that the average time between starting vaginal sex and ejaculation was between 33 seconds and 44 minutes!