It may involve sexual penetration or non-penetrative sex (for example, intercrural sex), and its penile-vaginal aspect is an example of ventro-ventral (front-to-front) reproductive activity. It is commonly associated with heterosexual sexual activity, but is also used by same-sex couples.The missionary position is the most common sexual position for couples, but is not regarded as the most favoured one. The position may also be used for other sexual activity, such as anal sex. The missionary position or man-on-top position is a sex position in which, generally, a woman lies on her back and a man lies on top of her while they face each other and engage in vaginal intercourse. Wikipedia (0.00 / 0 votes) Rate this definition: