I can come 2 or 3 times per session, but I don't always need to. I read a book on the Tao of sex, and it suggested that you need a 30-second or so break of only very mild stimulation once you come off the high before you start climbing again. I've found that to be accurate for me, so I just kind of rest, moving very slowly (like if I'm astride) so that I don't shift gears into "done" mode, and then it goes from there. If I try to power through, with a partner or on my own, I can rub for an hour and get nowhere, rubbing myself raw in the process--the break is key.
I have to say, as much as I've appreciated the generosity of my lovers in trying to get me to 2 or 3 or more, sometimes it's a burden. Sex is not a competitive sport. There's a fine line between generosity, which is lovely, and ego, which is less so. I think men sometimes get into the mindset that they're superstuds if they can get you to come more than once a session, and it becomes about them instead of you. And that's where female performance anxiety comes in--if he's invested in a specific out-come, pun intended, of sex, then you feel like he'll be disappointed if you don't. Sometimes, though, I just want to get off the horse after one. If I didn't think you were a superstud to begin with, we wouldn't be naked together, you know? The fact that we're having sex at all means you won.
Just because women are known to be multiorgasmic doesn't mean they have to be, or that it's a standard they must try to attain. SweetLady's right.