Amazing Session in a Side-Sleeper Position

I've been experimenting with different positions in the 18 or so Aneros sessions I've done so far, but my general go-to has been on my back with pillows underneath my back to elevate my butt and make sure the Aneros has freedom of movement and with my legs bent and feet planted on the mattress. However, even though I could get good stimulation from this position, there are some problems with it. Mainly, my legs would start shaking uncontrollably and I would have to use both of my hands to stabilize my legs, which is a distraction that took me out of the moment. I've tried various things to rectify this - putting my legs flat against the bed, using a weighted blanket to restrict the movement of my legs, etc. Ultimately, all these solutions restrict the movement of the Aneros to a greater or lesser degree.

Last session, I tried a side-sleeper position. Essentially, I lie down on my side and swing my top leg over and keep it bent, while keeping my bottom leg straight. This keeps the Aneros totally free of obstruction and my legs are unsupported by any muscle activation since they are just lying one on top of another so the shaking is no longer a distraction. What really surprised me is the feedback loop this position created between my prostate and my penis. Every time my PC muscles would contract and the Aneros would move inside of me, my cock would twitch as well and that would cause my penis rub against the fabric, which caused the Aneros to move again. I've definitely had long periods of involuntary pleasurable contractions in other positions, but because of the double action, I was feeling pleasure twice as frequently. So frequently that I was almost staying on that "high note". The only piece I haven't figured out yet is getting a better material to rub against. When I discovered this I just had a towel, but I'd definitely like something less rough.