Losing Involuntaries after full erection

... snip ... Is there a way to get past losing them with an erection, or is this suppose to happen? Does something change internally during an erection ( aka its no longer hitting the right spot)? ... snip ...

Being erect, chubby or flaccid isn't really something to be concerned with during an aneros session.

I think you're right about an intense erection messing with your internal geometry. remember that when you erect, about half of the engorgement is inside your pelvis in the Crus and Bulb of the penis -- http://en.wikipedia.org/wiki/Bulb_of_penis --. Those erectile organs occupy pretty crowded real estate, immediately below the prostate and just forward of the anus. So the rectal wall gets a shove from the erection and that in-turn may disturb the relationships between your Aneros and prostate.

The classic suggestion here is avoid touching or even focusing on your penis, strive to relax and allow your involuntaries to have their own way.

Please don't get mentally tangled up in this situation. Just relax through it and give it a few weeks to resolve

Don't even pay any attention to what your penis is doing. Though hard for us males to do, just let what's going on there be totally out of the picture and instead focus on the internal sensations you're experiencing. Early on, I got really up tight about whether my penis was going through the cycle of chubby to erect I expected it to do, and when I could finally totally ignore that and sense the more subtle feelings going on inside I started making progress.

Turn off the lights, lie fully undressed on the bed, and close your eyes and if you feel your penis moving or changing shape, just smile and enjoy that as part of the sensations your producing.