Most couples find it difficult to do a TRUE "72".....properly.
It takes a taller woman leaning forward over a counter-top, bar, pool table, etc ...........feet on the floor......chest on the furniture. She is being "spooned" from behind ......by a shorter man who is KNEELING on an bench (piano bench, chair or stool)....with his head/chest laying upon her back.
It is much easier laying down if the height differences make it too uncomfortable.
Now the "73" is a KILLER ...........and nobody has ever done a true "70".........well,maybe over in India or at the Cirque Du Soliel.