Double penetration: When a person is entered or penetrated in the vagina and/or anus by two people at the same time.Not to be confused with ménage à quatre (literally, 'household of four').
Not to be confused with ménage à trois (literally, 'household of three'). Many swingers argue that non-swingers have conflated the terms because of lack of understanding and that there are distinct differences among the terms with specific meanings as to number, intent, sexual orientation, and familiarity of the persons involved.
In principle, any sexual behavior performed by more than two people can be referred to as group sex, but various terms are used to describe particular acts or combinations of people.
