Is it possible for girls to pee without knowing it? Particularly if there is a fair bit of heavy fingering going on inside her, or pushing against the front wall during sex could the pressure force it out without her noticing?
I'm pretty sure my gf has let out pee during fingering/sex at least a few times, but when I brought it up she said she hadn't. Its fairly distracting for me..


Have her go before you start. As I understand it, this is more likely her about to achieve an orgasm. Tell her to relax and let the feeling pass.
Yes, it is possible. When "fingering" you are pressing against the anterior wall of the vagina. Just behind is the urethra. Irritation of the urethra gives a great urge to pee even when we do not have to. SOmetimes some leaks out. This feeling will not pass as long as some klutz is blithely rubbing away.
Ok so I need to get her to pee before we start.. Shes in a very frustrating habit of holding it in all the time and very rarely going to the toilet, even though I tell her its not good to do so.
Sometimes, I've noticed that if my wife has a really strong orgasm (they seem to vary quite a bit in strength), she will, um... leak. I'm not sure why, but mixed in with sweat and vaginal fluid is something else, and in copious enough quantities to make it inadvisable to have sex on a fabric surface. I wouldn't ever ask her to fix this, so I just plan for it. It's all part of the game.
It could also just be her relaxing during the session. When the muscle tension leaves, some less than pleasant things can come out.