Two weeks and she thinks she’s putting a flag on his shores.

This is the woman's biology almost working against her. Chicks like this really want hot guys, and when they land one in the top 10%, and they fuck early on, she immediately gets emotionally attached (unless she has a very long list of historical lays; the longer the list, the less likely to have this emotional hook occur). When that happens, their biology and psychology kicks in to say "okay, he's ours, no other women allowed." No logic or rationale is involved, and that's not a disparaging remark, I'm not saying there should be, that's simply how it is.

Then the wild fantasies in her mind start taking flight, and the longer these two are around each other, the longer and more in depth her mind creates these fantasies. If/when the guy moves on, even though he only saw it as a relatively casual thing, by this time the shattering of these fantasies and the emotional bond she formed with this random bring her a truckload of angst and pain. This does nothing but make her future behavior even worse, because after this, it makes her even LESS likely to successfully form an emotional bond with anyone, and she tries chasing men who are even MORE chadly than the last Sir Chaddington, because she really wants to feel the magic of "that spark" again. And the only way she knows how to do this is follow the same method that brought her to it originally: try to sleep with random hot guys.

Thus, the process repeats. The vicious cycle continues. And the men who understand this, the sexual realists, they simply sit back eating popcorn, watching the big screen, occasionally turning to each other and jabbing the guy's shoulder next to him saying "haha, you see this shit? Man, this is something right here."