The shaking that I see is like when they are having a "spirit filled" experience lol. It comes with no warning.
Every so often when having sex with a provider, or lady friend, some like to do the loud moans, and make a loud publicly announcement they're about to come. This use to always make me walk away feeling good, because as a man I felt like layed the wood, and layed it correctly.
However as I've gotten older, and have learned the female body, and emotions better over the years, I now can figure out a lot of the times if a female is just actting like she's coming, and when she really does comes.
Ladies and Gents have you learned how to figure out if the person(s) your having sex with has really come, or are they just doing a lot of load moaning and groaning
The lady might make that noise. I know do to the shakes she has. They are uncontrollable, it like there whole body twitches. Other times they can be more silent and pussy gets soaking wet.
"I'm coming" 99% of the time. If you think there is much more than just moaning and groaning, you have a great actress or you are the 1%. I will admit that the squirters make it a bit more difficult to tell.
And, yes, there are ways I "know" when a provider is actually coming, although I assume there are ways to fake even these signs:
1) She squirts. Can it be faked? There's nothing definitive on this to my knowledge. I know some girls who taught themselves how to squirt, so I assume they can control it to some extent. But when there is simply a gush of pussy juice, it's a pretty good sign. Once, a gal I was with gushed and then I slapped her pussy and she screamed and squirted a full foot in the air. Was she faking it? Unlikely, IMO.
2) The inside of her pussy writhes and contorts. Is it possible she's doing a Kegel around your cock? I suppose.
3) What the other poster said: certain body shakes, shudders and trembles. Fakeable? Yes.
And if she's able to combine all the above and still be faking? Kudos to her. She should be in Hollywood and goin' for an Oscar. If the illusion is good enough to fool me, why should I care?
The shaking that I see is like when they are having a "spirit filled" experience lol. It comes with no warning.
Just remembered one sweet little gal I was pounding from behind when she started sucking on her thumb and yelling "fuck, fuck, fuck, fuck, fuck!" Acting? Maybe, put if so it was damn fine acting!
To respond to your post....
1. I do sometimes squirt without an actual orgasm, so it is possible at least for me. It's not "on demand" at all, and only works with vibrators. I don't expect that this is common, but thought I'd mention it.
2. This is completely possible - and often a really effective way of encouraging a gentleman to have an orgasm.
~ Naiya
but your 1% estimate is far, far low. No, make that far, far, far, far too low.
I walked into your door and said ok.. I am here I want you to cum.. does that make you feel pressured.. Does it make you wonder if she is ready for you to do your thing and leave?
Why would it be any different for women?
Gentlmen spend so much time and energy trying to MAKE a woman cum.. It takes all the fun out of it.. I like power as much as anyone and being able to do that to a person ROCKS! I do get it
But, if we spent all that energy on enjoying the momment and the give and take. I suspect most women would not feel pressured to fake it....
And what better way than to give her a great mind blowing O!
I personally don't give a shit, sure it's great if she does but it really doesn't affect my session either way. I give her my all (pun intended) and if it happens great, if not that's fine too.
No pressure.......No regrets
with my faves I never expect them to have to cum and most sessions it doesn't happen. Then on occasion I will show up and she will be in the mood to cum and on those occasions you can tell its real, firstly because it is extremely rare for them to cum without taking charge to some degree and helping out. Just like I can't cum until I get the position just right with the right amount of friction, I have notice the same for my faves. when the pressure to cum is not on then you can tell when she really wants to and is not faking it.
Easy as that. It is understandable why you ask the question, as we all do. But I find it pointless, and if you are looking for the truth you will find it discouraging.
Some ladies come, many do not. Any provider who is good knows how to emulate or summon excitement and O because it excites us and helps get us off. If it is a good performance, hot and believable, just relax, enjoy it and stop searching for tells.
The true answer is that it happens a lot less than you think. Whether it does or not usually does not have that much to do with you. First off, most ladies hardly ever come, many never come, and some come all the time. Those that never and always come - nothing to do with you, it is all about them. Yes, you could be the guy who gives that lady who rarely comes a crashing O, and feel proud about it.
I prefer to take it at face value, enjoy the moment, not pretend I am a great lover, or worry that I am a lousy one. That works for me.
zig
Recently , I spent time with a man ( hobbyist) who
told me how he could tell a woman was actually having
an "O" . He explained to me that our body temp rises a couple
of degrees and that he can feel it . He was right !
A few that I have been I have noticed the same thing. I have also noticed the pussy gets hot sometimes, lol. The heat feels like a massage on my dick. I love the involuntary reactions where the lady's body shakes or buckles like crazy like she is have a deep "spiritual experience". Fun you have them on the stomach like this and the her butt pushes back to have you go deep while she yells out and shakes.
for some women the skin on their chest between their boobs and collar bones turns bright red. It's completely involuntary.
Just tell her upfront a big fat TIP is awaiting her, if she cums!!
Angela, that does work with many women's bodies, but not all. Some will get warmer when they get very excited even if they do not cum, and some do not get warmer even with a very big O. There is almost no "proof positive" symptom but there are several indicators, for example many ladies taste different after an orgasm.
It definitely depends on the female. Some cum very easily, while some cum on rare occasions. I know for me, it takes a lot of energy and concentration for me to cum and I'm completely drained afterwards. I don't think most hobbyists would be ok with me stating that since I have cum already, now I want to sleep. Then there is also that added pressure when someone asks if you are about to cum. What am I supposed to say, no?
That's not to say I don't cum in sessions but I also don't see why it matters. I am here to make you cum. If I cum and you want more than one pop, then I'm useless for the rest of the session, and the hobbyist typically feels cheated.
I also doubt a lot of claims of knowing when a lady is really having an orgasm. Some females don't become really wet after cumming. Some don't have the after shocks. Some can be very vocal and some are really quiet. There are no signs that work for every female. And a lot of "signs" can be faked, regardless of whether men want to believe it or not.
At the end of the day, if we both have a good time, who cares? And if only you have a good time, still, who cares? I have a goal at the beginning of any sessions, and if I accomplish that goal, then I'm going to feel great afterwards, whether or not I came.
...to just not care. I mean who's paying whom anyway? If she comes, she comes, if she doesnt, she doesnt.. she isnt your wife or your girlfriend, and her getting off is her own responsibility (if she's a good provider, she has plenty of opportunities & cues for it anyway 
Focus on yourself and your own needs first
Since you/I are the ones paying the bill, it is not particularly important if SHE has an O (or as in so many of the reviews she has 2, 3, 4 or more) or not. I care if I am satisfied for the time I have spent with her. Some of the gals can really put on a show, and for some guys that is what gets them over the top...and frankly that can be quite intoxicating.
But I have yet to go and see a gal for a follow up simply because SHE claims to have had an O. But it certainly is more entertaining when the gal seems to be into the scene as much as I am, and if that means giving off those "moans and such", then that is what will bring me back. Whether she is achieving a "real O" is something that I really don't need to know.
But also, I enjoy DATY and that is a bit more entertaining in seeing if SHE really achieves an O. But even with all of the prior comments on how to "know for sure", I still can't be absolutely certain. And I suspect until SHE suggests that I come over for an OTC to "take care of her", I would highly doubt that she is all that mesmerized with my skills (at least this hasn't happened so far).
One thing that I am very confident in saying is that many providers have faked an orgasm for me.
Does it really matter? Not really - if a provider gives a convincing act, that usually works for me.
When I see a provider for the first time, I don't know 1) how easy it is for her to come with a man she is meeting for the first time, or 2) what she is looking forward to for our date. My observation is that some providers anticipate the hobbyist bringing them to orgasm sometime during the date, and some don't. That's part of the appeal of meeting new providers - you never know what is going to happen.
I can think of a couple of situations where the provider and I were just not on the same wavelength. In both cases, the providers brought themselves to orgasm while I concentrated my efforts elsewhere. Still highly erotic and memorable, and part of the adventure of the hobby.
I could tell she was not acting because I told her to get off.
The girl's looked pretty hot on the photos. There was one detail I ignored -- she is at least 5'9" and I am only 5'7". Once in the hotel room, she got undressed quickly and recommended cowgirl. I had some hesitations because of her size (not fat but definitely a big girl); nonetheless I agreed. It wasn't bad until her hip movements gotten to the point I did not feel comfortable, so I told her to get off me. She did say something like that "I'm coming". The next day I felt the base my penis like having some muscle strain; that lasted a few days.
I just do it! He can tell by the watery/frothy stuff left on his sheets or his hands! (wink)
That a woman's clitoris retracts just before orgasm. Get with the program