A slight momentary loss of consciousness.
The constant, hard, rhythmic pumping and convulsing of all kinds of muscles in my pelvis and around my cock, I can feel my cock pulsate hard, my anus puckers extremely hard and its all uncontrollable.
I get a light-headed kind of feeling all over in my body when I shoot cum exceptionally hard and far; the orgasm is airy yet so powerful I feel like it cut off a lot of my body from itself, and THEN orgasm begins after a few seconds of cum shooting out and all the rhythmic shit begins differently and I wind up cumming for well over 30-40 seconds.
I can feel the blood race to my genitals and feel my cock swell larger than normal, that is when I know its really gonna be a massive orgasm.
I whimper, moan, curse, huff and puff and enunciate all kinds of stuff when I'm losing it during orgasm.
I tend to thrust my hips and jut my cock forward uncontrollably depending on the position I'm in. I have no conscious control over this movement. When its a massive O I wind up with sore and pulled glutes sometimes!
Lastly, my ejaculatory orgasms last sometimes up to 1 minute or even longer depending on the kind of sex or self pleasuring that is happening. Distinct pulsations, cum is coming out of me, writhing uncontrollably in bliss-agony. That's how I know I'm having a super intense orgasm! I don't want to say I cum harder than a lot of guys out there, but given what I've read and seen over the years, I'm on the up-end of the scale as a massive hard cummer
my wife sometimes gets scared if I'm going to make it out okay when I'm done, I cum so fucking hard sometimes she worries for my life! I tell her "you can go even harder on me the next time"