This decision is often made after one has had an outrageously dirty weekend with uncountable hookups. While it can relate to both males and females, the term itself is quite masculine. Furthermore, males, typically being the social initiator, bare most of the weight in such scenarios. Thus, this term applies more to them.
A "Mann. What a crazy night. How many girls did you hook up with?"
B "I don't know man. I lost count after that chick that looked like she had vomited in her hair. And that hot blonde chick, I didn't even get her name before we hit the bathroom and before I knew it she was gone.
A "Yea man. Enough of this bullshit. We need to enter Operation Settle Down before we contract an STD from these orgy weekends."
B. "Yeah i know i barely lasted one day."
A. " gawd you are a whore, so Operation Settle Down was a fail"