And you won't be dripping sweat on each other. It also provides plenty of face-to-face intimacy that's missing from spooning, at least without having to contort your body around.

Like spooning, it reduces the muscular demand on both partners over its vertically-oriented counterpart. Also called 'reverse spoon' (even though it loses all 'spooning'), side-by-side is like missionary rotated onto its side.