IndianaJones,
Yup, I can relate to what you're saying. I squirted for the very first time at the age of 42, 5 years into my relationship with a FB / lover - out of nowhere there it was. We were both really confused. Next time we met it happened again, but this time I felt it was not the vaginal liquid explosion I sometimes get (is that gushing vs squirting?), and I seriously wondered whether I'd peed on myself. I was confused and embarrassed - he was confused and slightly worried. Next time I suppressed it - shifting position.
But the more I thought the more I knew it wasn't peeing. I have that same "valve" thing that guys get - if I'm aroused I can't pee (have spent many frustrated minutes trying to calm myself to pee). Don't know if all women have that, but sort of sounds like your girlfriend does since she couldn't pee.
Googled, investigated - penny dropped - could be squirting. Researched further (Red Tube more than Wiki at this stage) - yup, I'm squirting. Was then still not comfortable with it - partly due to my FBs total lack of excitement (funny scene where I stand there emphatically telling him - "listen, go and look on Red Tube").
Then that summer I had heated sex with a new lover. He loved my orgasms and got completely into the sex - which then got me really going, and I squirted. He was shocked, looked at me with wide eyes and said "did you just squirt?!" I sheepishly said yes, whereupon he literally jumped out of bed, did a victory dance (complete with bicep flexing). Back in bed he kept going on about that being every guys dream, his life-long dream, that he felt like such a high performance lover.
There and then I decided that I love it, some guys love it so I'm gonna do this despite the less positive reaction of some guys, and wiki describing it as "probably incontinence" (like hell it is - I've been pregnant and experienced the slight incontinence most pregs do - this is something completely different).
I find it interesting that your GF squirted when you were FBs, but not now. Sex is different in those two relations - when feelings are involved then a great additional element of sex is the strength of feeling. Could it be that she feels that the intensity of squirting "distracts" her from savoring the feelings? I know I can be like that in relations (vs with FBs). With me it's anal sex - never had it in a relationship, have literally begged a FB to do it.
Think now, older and wiser - and having experienced a relationship where sex fizzled out - I would do it differently.