TOPIC: Trimix Injections with Filler

About once a month I use filler when my wife and I attend a swinger event. It helps overcome performance anxiety. I always have the antidote handy . 

Ive found that I “miss” the corpus at least 50% of the time.  I think it’s due to the residual filler I have making it nearly impossible to know how to inject it. Does anyone have experience injecting trimix with filler? Any tips for how I can make sure I’m hitting the mark each time?