The ins and outs...
You: Think back to playing wheelbarrow games when you were a kid, nd imitate the position. Use one or more pillows to help you get the right height.
Him: Stood behind you, holding on tight to your ankles. He bends your legs in and lines your thighs up with his.
Why is it so good? The element of surprise! Out with the laws of gravity and normal entry points. With your head upside down, you'll feel pleasant lightheadedness combined with intense sensations caused by the penetration from behind. Not forgetting the unobstructed view of your derrrière he gets treated to!
A good time to try it: When you want a break from routine and want to show him all those yoga classes are really worth it, in more ways than he imagined!
Tip: So you don't get too tired, lean on your forearms, not just your hands. Lift your head regularly so the blood doesn't rush too quickly to your head. Now's not the time to feel faint!