The best way to put it for myself is if I was to rate the hardness of my erection throughout
Prior to anything, I’d start soft and limp, or 0
Once teased I’d work my way up to a 10
After my first orgasm, I’d be around an 8, still firm enough for a fucking
After my second, I’d drop down to a 3, which with a little foreplay could be brought back up to 5 or 6, depending on how long it’s been since I last properly emptied my balls.
Sometimes I could manage a third orgasm, and at this point I drop to a 1 or 2, from which I’m done.