I'll begin with few words about me, i'm a fully trained contortionist (mostly a backbender for thoses who knows a bit about contortion), i can do all oversplits and headsit quite comfortably now. I have an average body type, neither fat or thin, tall or small but i'm well equiped, about 10 inches when i'm all hard. Also, i'm lucky to have an amazing gf who share my interest in contortion and practice herself. Actually she is the one most interested in frontbending and me sucking my own cock
First time started during a regular contortion training, doing the usual splits, handstands and backbends and my gf asked that we do more frontbending than usual. So we started with forward fold and legs behind head poses and when trying the one where you try to get your foot behind your head under the opposite armpit, we noticed my head was real close to my crotch. I removed my clothes and went back into position with both legs behind my back. About this pose, i'm surprise than most guys use a different way to reach their cock. Have the leg behind head allow you to push with the legs for extra flexibility and i think less pressure on the neck. Anyway, i prefer it that way and my gf too. Back to the attempt : I was nearly about to reach my cock even if i wasn't hard yet, and with some help from my gf about this i managed to get the head of my cock in my mouth! That was really weird! I never thought of trying this before but it ended to be quite interesting. My gf was really excited about it and decided to try for herself (unfortunatly she never managed to reach her own sex). We found a dildo belt she could use to try to imitate me.
After training it a while, i got better and better at it till i could swallow that much of my cock that it touched the bottom of my mouth. That's enough length to comfortably suck and play with my cock. I was thinking it was the end of this but my gf showed me that she could swallow much more than i do, my whole cock, by deepthroating. She never had done this before that day, but she trained it as she expected me to reach this limit and she wanted to help me go even further. She showed me how she trained it with dildo and after fews tries i managed to relax my throat to let the dildo go down. The gag reflex is really tricky!
Few days later, we decided i should give it a try. I did a really good warm up, and it was time to try deepthoat on me! I went into position, legs behind head, cock in mouth slowly reaching the back of my mouth but as my neck was really compressed i didn't manage to relax my throat. I tried again but this time i had my leg lower against my neck, nearly on the upper back. That way my neck is a lot straighter and relaxed it's only harder for my hips. My cock entered my mouth easily, i was excited and relaxed. So it happened, my cock went down my throat! An incredible feeling! I dont like the cum taste but i went in and out few time sucking and playing with my tongue till i finally cum in my throat, no problem with taste there, only warm wonderful sensations. It's totally crazy to deepthroat yourself, i totally recommend you to try haha
My gf also managed to get to this level with her dildo belt, probably even better than me nearly to the bottom of it (i never went to the bottom of my cock, i don't think it's possible for me). It's less good for her, but we both enjoy doing in together
Being 43yo is fine to train contortion, probably you will not achieve super advanced moves (unless you have super awesome genetics) but you can do very cool poses. I think all splits are totally possible, legs behind head stuff, even a cheststand. Be prepared to train a lot, contortion is a serious commitment, it's rewarding tho You'll really enjoy being able to move so freely!
And good luck for deepthroating your cock, it's really a surprising feeling as the throat will have to stretch as your cock will go down. I'm still working on getting my own cock down to the base but i'm not sure it's worth it. My gf wants to see me do it but for me i can already suck more than enough to pleasure myself Anyway i'm always up for a challenge!