I have thought about this topic recently and I have to finally came to conclusion that is logical. I've asked men and women in my area and they could not argue with my logic.

When a man has sex with a woman, his orgasms have a pretty steady baseline. No matter who he is with, how hot she is or how "big or small" her parts are, his orgasms will remain on this baseline. It may vary slightly, but for the most part, it stays on this baseline regardless of who he is with.

However, the female orgasm varies wildly from gravely disappointing to black-out euphoria depending on her partners size and skill and this is where a female becomes a slut. She will actively seek a better orgasm from a person every time she sets out, looking for a new sex partner with different sized sex parts and sex that involves new and exciting positions. Like an addict, she will keep searching for that greater high, even though it may never come because she's already had the best there is and the best "fit" for her body but that doesn't matter. She needs to find that better high. Forever chasing the proverbial dragon if you will, leading her to be a.... A slut.

As to where the man, knows his orgasms are within a specific range, knowing, for the most part, when he has found the best available partner and so logically reacting by NOT chasing a high that won't get any better But simply having sex because he enjoys it. Not because he is looking to have a better orgasm with the current partner than the last. He is just looking to have an orgasm.