Such an interesting thread because I'm automatically asking why you need to know this? I think channeling your energy into providing a mutually satisfying experience for both of you rather than anxiety over whether she's faking it would be time better spent!
I have never faked an orgasm in my life. I can be brutally honest and probably to some people just unkind but I prefer my partners to know that yes, I am enjoying their attention immensely. Let's just take that and enjoy it.... Or no, this really isn't working for me but I'm still willing to make it fun for you! Our bodies can be assholes sometimes and just won't let it happen. Other times we're just not feeling it and forcing or pretending just produces a hollow encounter for both of us.
Lack of confidence or knowledge about women's responses can cause some guys to be anxious over whether she orgasms or not ... I think this is why most women just give them what they need rather than prolong the ordeal. I think this is misleading and detrimental in the long run.
As to the actual signs every woman is different. I articulate how it's building, my breath quickens, I'm really noisy and will moan a LOT. Every muscle tenses and I'm probably going to rip up the sheets or scratch your back if you're driving me wild
guaranteed you will be soaked as I do tend to gush buckets the more intense that orgasm is ....
Some women get really flushed and others get really quiet and internalise that pleasure! So as each woman is different so are their responses.
The older I become and more sexual experience I have the more I realise that sexual satisfaction is less about the destination of orgasms and so much more about the journey along the way. Take my advice ...This attitude will change your sexual experiences completely!