yes
watch the last trick in this video
(Link moved below.)
To grind on a guy while lying down, first ensure both of you are comfortable and in a relaxed position. Position yourself on top, facing him, and use your hips to create a gentle rhythm, moving back and forth or side to side. Communicate with him to ensure that both of you are enjoying the experience, and adjust your movements based on his reactions. Always prioritize consent and comfort for both partners.
gravity
gravity
Don't Let the Bastards Grind You Down was created in 1997.
Yes, bikes are safer than a skateboard because you can fall down when you do a flip over and you have to keep balance on a skateboard but you can hold on the handles and sit down on a bike.
Lying down.
I assume you are referring to inline skating. Yes you can grind without a grind plate. The plate is used to slow down the wear of your skate frame.
"Lying down" in French is spelled as "allongé".
"Porridge" (1974) "Saturday Night and Sunday Morning" (1960)
It looks like someone lying down, either fully down or leaning back/reclining. You could be lying on your side or on your back or sitting in a reclining position like in an easy chair. Ever see anyone riding a recumbent bicycle? See the links below for demonstrative pictures.
Prone means lying horizontal with the face down. Pronation is the action of lying prone.
Won't Take It Lying Down was created in 2000.