Half-body orgasm? (Strange!)

I've recently started using Aneros massagers again after taking a pretty long break (well over a year and a half) and everything feels so different, it's amazing. My body seems to have picked it all back up quickly, which is great.

Today something really wonderful but odd happened. After around an hour or so of gentle pleasure I felt my prostate swell quite considerably and I could feel my body start to rub itself against the massager really gently. I began to feel light headed and really far away from my body, which isn't uncommon for me. I nearly always get a very soft pleasurable sensation on the inside of my left thigh at some point, and sure enough it began feeling really nice on my left thigh just after my prostate swelled. But this time it came on really quickly, and it soon became quite an intense feeling. I relaxed and just let my body do its thing.

After about 30 seconds of this the left side of my body sprang in to life. Both of my legs began to quiver/shake so quickly, like a really intense shiver, and I involuntarily clenched my left fist. My prostate began to send out waves of pleasure, which I could feel mostly on my left. (Like a 90/10 split.) My left arm began to feel really pleasurable, just like my thigh, and then I began to feel a super intense feeling in my left nipple.