Guys who admit to this, please also also tell us if you are circus people or not.
I’m sure someone has called me a clown before now, but not to my face that I can recall.
57 year old male. Done this all my life. Only on my left foot though.
I just tried sitting on my *right *foot and it was immediately uncomfortable and almost painful. Weird.
I’m a male. Pretty skinny and very flexible (not to Circus freak level though).
I’ll sit on my foot frequently. Often its to get a bit higher I think. But I do find it comfortable.
I also prefer peeing sitting down by far. And I hate sports.
John Wayne I am not.
I do it and I’m a bloke.
I think.
I’m:
41
A wee bit overweight
Kind of active and flexible (I dance Lindy Hop regularly)
A computer programmer
Much like someone else said, I’m right handed and usually tuck the left leg under me. I am doing it right now, as I type.
I sit with my right leg tucked under me sometimes, usually while on the couch, sometimes in my chair at work. I’m trying to quit, though because it puts my left hip out of whack. I have no idea why I sit like this, I’ve never thought about it much.
I’m a tall female (well 5’8") with short legs and I sit like this all the time. It definitely feels better much of the time than the natural angle of the dangle of my leg.
When I am driving on a long trip I often put my hand under my thigh. Something about that little boost in angle really relieves pressure.
I’m a 5’4’’ female, and I sit like this occasionally. My computer chair doesn’t get high enough for me, so I sit on my foot to give me more lift. More often I sit with both feet under my posterior (kind of seiza style) and hold the side of one foot with the toes of the other foot.
Grandpa wasn’t. Stayed pretty slim all his life; not sure how tall he was, “on the tall side” for his age group but not extremely so. He was a Merchant Ship Captain and worked as his city’s treasurer for several decades. About as far from being a circus person as they come, but from what I hear he’d consider it a compliment to be mistaken for one 
I’m left-footed and the ankle that gets tucked up is the right.
I’m not very tall. The distance between table and chair, as a result, is just a little too big for me. Every table, desk, counter, off just enough not to be really all that comfortable to write, type, eat, etc. The simplest solution, for me, has always been, to sit on one leg. Voila—now it’s the right height!
Standing at a counter that’s a titch too high, or having your feet not reach the floor from your seat makes one feel less than adult, no matter your age.
As I get older, my ankles and knees are less accommodating to this activity. I may need to find a new strategy.
Left & Right footedness… Can that be a word today?
When teaching people to water ski on a salomon ski, they learn faster on average if right handed people put their left foot in front & vice a versa…
Also people who have had ballroom dance lessons will put the left food forward & learn faster that way.
There are not an insignificant number of people who do it the other wayt but on average…
YMMV – ya ya, I know people that are right handed & right footed, but … when teaching water skiing…
The what? 
I think don’t ask is talking about that model pose where they place the legs in an almost-crossed-feet position. It visually softens the curves of the leg shape; add being propped up on something so feet aren’t flat but continuing the line and even I look thin. It’s similar to the starting position in ballet with the feet in third position (a search for “ballet feet position” says).
I sit like this all the time. I’m 5’5" if that helps. I think it’s more comfortable than both feet on the ground/
BTW, my feet are naturally pronated. If I lay flat, my feet will turn outward.
Not a circus person. Thin, and fairly flexible, but it’s not like I do yoga or anything. Thinking about it, it may be difficult to do if you’ve got big thighs, but I’m not sure.
It’s looking like handedness may have something to do with which foot you tuck under.
I’ve never had anyone comment on my doing this, so I never realized it may be considered odd. It’s just comfortable.
It takes pressure off the tailbone. I have some kind of congenital malformation of mine, and it gets really sore, so it’s definitely worth the relief to have my foot fall asleep.
I’m a guy, 59, and I sit like this all the time. Almost always my left leg goes under. It takes the pressure off my butt, because the leg goes under the top part of the thigh rather than right on the points of my boney butt. I sit this way for hours when I’m reading at home.
Who cares, its hot. I’m into weird things.
I’ve done this all my life. (5’2" and …uh…chunky, so it’s hard to cross my legs now), but I do the tuck and sit on foot thing still. Foot falls asleep, and getting up onto my feet can be a bit painful, ow ow ow. I do the sitting-like-an-Indian double tuck, too, but not for too long.