Last night I decided to leave Sup Forums for good after 3 years. Too many people here are crazy, extremists, bitter /r9k/ virgins and it's just a generally negative environment to spend time in. I've outgrown it, but I'm going to make one last thread to destroy a bitter neckbeard myth here.
There is no evidence that casual sex with more partners makes a woman less likely to stay in a stable marriage.
First of all, lets look at the graph which is used the most with several others like it. Right off the bat, it's intervals on the x axis are not consistent, so it makes the correlation seem much more dramatic than it actually is. It basically levels out at 5 if you were to keep the interval at 1.
Another immediately important factor is the first category. There is a significant difference between this category and the rest, but it's not why you think, I'll walk you through it. This graph is all married women, if you are married and have had no other partners in your whole life, you're still fuckin married. The women who divorce their original spouse end up having sex with someone else after their divorce. Inherently the married women who have only had sex with one man are still in that marriage. This does not have to be the case with the other values on the x axis, therefore it leads to a higher number for the 0 category.
Lets get into the most important and obvious flaw in your sexless logic. The link you're making here is equating correlation with causation. That is something that is on your first test for stats back in fucking high school, there is no excuse for not understanding the concept. You need more than just a correlation to argue any causal relationship. It's entirely possible, and I think likely that the independent variable is happiness and not number of partners. I don't think it's a stretch to say that being unhappy makes a woman more likely to have a higher than average number of partners, and more unlikely to stay in a long term relationship.