Hah! That must be a difficult balancing act. I wish my cat was more inclined to use me as a jungle gym. Sometimes she will walk on my back while I'm sleeping. The paws feel nice, as they apply her entire mass to depressing small areas of my back. It's like a short-lived massage.
Other times, while I'm lying in bed, she'll prod my face with her paw, with claws extended. I think she does this because she likes movement, and she realizes that this maneuver induces me to move. Her claws are very sharp. My mom wants to clip them but I said, "don't you EVER do that to my cat".
Yeah she only recently started doing it. And yes, for some reason my cat has horrible balance so when she's on my back i have no choice but to lay still so she doesn't slide off. I know what you mean about it being relaxing too - there's such a thing as goat yoga where little baby goats will jump up on your back while you do your yoga.
Wow I may need to try goat yoga out next time I'm in New Hampshire.