
Well, I have sucked myself now like 4 years and I'm 21 years old. I started with basic Bottom-Ups style and succesfully did that for months althought i couldnt get my dick very far in my mouth. Then i tryed new positions but none worked out. So I svitched back to Bottom-Ups. That position wasn't that great because blood comes in your head and it was difficult to put that penis in to your mouth unless you had really good force (witch were my legs in the walls) and even then it was difficult.
So I thought that if I could get somekind force to help me get my upper back close my penis then i could basicly get my dig in mouth in sitting position because i was pritty sure that i could strect that far from Bottom-Ups experience. So I first thought that if I put something heavy on my neck then it would help, but damn that's just too absurd.. So i tryed to figure out and then I suddenly got idea, and by idea I don't mean that I called friend for a help.. It was something even better.
Well, basicly I came middle between 2 walls as in U-position. So picture would look like this --> |U| |=walls and U=myself. I was holding my legs far up in a sitting position and I had wall behind me. So basicly my head and my butt touched the wall and back of my toes touched walls too. And from that position I raised my butt up so it touched that wall and basicly my penis and my mouth was in same degree each other.
From that position I had my over half of penis in my mouth, I didnt need to use any body force to keep me together, My stretching position didnt hurt one bit. That layingsit position is very relaxing. I can blow myself or masturbate while sucking my upperpenis with my lips and cheeks (dont know whats that red thingy in english). Also I could suck myself from that position even hours without getting exhausted or anything, or well not hours, I'll throm my sperms inside my mouth faster then u know.. But then again I had 3 orgasm in row though with few 10 mins brake in middle

Sometimes I put strong lightining and mirror infront of me, which really turns me on. That big mirror is pritty close to me, touching back of my balls.
The problem is that how you build yourself in position, maybe I can later on post some pics if anyones intrested i mean how i builded myself into that position. Also note that I was full naked, so of course there was something soft behind my ass and behind my head, especially behind head so you can also blow yourself.
Well if you wanna ask something go ahead, and tell me your experiences or post some post where someone used wall as force to help you suck yourself

EDIT: I also made this while I was stanging, that position where I could stare my balls, man its really best to have orgasm in that position or at least in my opinion. So its basicly like U upsidedown between walls.