Missionary position

The missionary position or man-on-top position is generally a sex position in which a woman lies on her back and a man lies on top of her while they face each other and engage in sexual intercourse or other sexual activity.

In general, early modern Catholic doctrine held that sexual relations were acceptable as long as they were within marriage, not done on Sundays or other church holidays, done in a way which would allow procreation, and did not upset the proper sexual order, which meant the man had to be on top (what has since been termed the “missionary position”).
Merry E. Wiesner-Hanks, Early Modern Europe 1450–1789 (2nd ed, 2013), Ch. 2 : Individuals in society, 1450–1600

One presumes that all of those jokes about the missionary position might have a kernel of truth.
Michael Ruse, Atheism: What Everyone Needs to Know (2015), Ch. 12 : The Meaningful Life

Bonobos and humans enjoy many different copulatory positions, with ventral-ventral (missionary position) appearing to be preferred by bonobo females and rear-entry by males, while chimps prefer rear-entry almost exclusively.
Christopher Ryan and Cacilda Jethá, Sex at Dawn (2010)