If you only try one, try this. Face to face, simple, and easy to hold.
Pillow spot: under her hips and lower back.
What changes: her hips rise to a gentle 27° tilt and stay there, start to finish.
Why it works for both of you: she rests on the foam instead of arching her back. He doesn't have to keep stopping to adjust. Fewer pauses, more closeness.
