Orgasmic Contractions?

Interesting questions.

I have had an extremely intense dry orgasm with my Aneros. I had a question. Since the prostate is filled with ejaculate when it becomes engorged, and orgasm causes strong prostate contractions similar to cumming, how does the semen not get expelled.

First, congratulations on such a quick transition into prostate based orgasms. For some men, prostate orgasms DO manifest as ejaculatory events, for others there may be a leaking of prostate fluid resulting in a dribbling emission of fluid, for others there may be a retrograde ejaculation back into the bladder and for others still there may be no emissions at all. The range of possible, 'normal', responses is pretty varied and as long as you are not experiencing any discomfort from your particular response, I don't think you need to be concerned.

If I touch my penis it does, so I know it's there ready to go if I touch my dick. It has to be going somewhere, doesn't it?

Penile stimulation does seem to be an ejaculatory trigger mechanism. This would make sense from a reproductory point of view as expelling sperm without the penis delivering it into a receptive female is biologically unproductive and therefore somewhat wasteful of the body's reproductive energies. Prostate orgasms may or may not result in ejaculations. When there is no ejaculation the prostate may remain full and engorged and more orgasms may be possible as many members of this forum can attest. Ejaculations typically trigger a prolactin hormonal response which in turn neutralizes the 'feel good' hormone dopamine and also releases the calming, bonding hormone oxytocin. This is the typical male refractory period.

Is it all just poring into my bladder or something?

Perhaps it is, you can check for this by observing your urine soon after experiencing your prostate orgasm. If your urine appears unusually cloudy following your orgasm then some retrograde ejaculation has probably occurred. This is really nothing to be concerned about as that too may be quite normal for you. If your urine is clear and you did not have any penile emissions, then your are still retaining the prostate fluid, it hasn't gone anywhere.

I am still pretty new at this, so I apologize if I sound like an idiot, lol. Thanks in advance.

That's quite alright, no apologies are necessary, we are all on this learning journey together. There is still quite a bit about male physiological responses (especially in the sexual field) which are unknowns. I encourage you to read through all the links I provided in my introductory PM to you, it will hopefully save you a lot of time and frustration. Good Vibes to You !