Thanks for the armor, Interceptor! I'll probably need it.
Anyway, I disagree about whether this woman can injure Iqqi. She can, and pretty severely, too. Here's why.
Everyone has times when they must have people around them they can rely on, and for the most part, when those times hit, we look to our friends or significant other. This isn't a bad thing. The problem comes in when we value our relationships primarily on the amount of cost sunk into them.
A sunk cost is an investment that cannot be recovered. In Iqqi's case, her sunk cost is the amount of time she's spend hanging around with Snake Woman, but what you guys call "oneitis" is also a sunk cost. Time and energy spent mooning about some woman who doesn't even know you exist is a sunk cost. You can't get it back.
People are extremely reluctant to walk away from a sunk cost. We hate wasted effort, and when we're faced with it, two ways of thinking kick in. The first is an overoptimistic probability bias. This is a tendency to be unrealistically optimistic about the outcome of things we've already invested in, and the more we invest, the more optimistic we get. "I spent hours planning our first date! It has to work out." Nope. Sunk cost.
The second is the requisite of personal responsibility, in which we attempt to make good our mistakes, which in this case might just boil down to a reluctance to admit that we're wrong. "But we've gone out for so long! I'm sure I can change this one little thing about her." Nope. Sunk cost.
What's the difference between a sunk cost and an investment? Sometimes we don't know until the dust settles. We can't avoid sunk costs. What we can do is reduce the loss involved, which is only possible if we're willing to admit we screwed up and keep those two psychological tendencies in mind.
When someone does something repeatedly, assume that that's just what they do and decide whether or no you want to tolerate it. Sometimes it's harmless. Everyone has their quirks, but for things like flirting with other people's crushes, or a boyfriend's friends, any investment in that person must, from that point on, be considered a sunk cost. Throwing more time, money or effort at the problem will increase that sunk cost.
Let it go, because if someone does something consistently when everything is fine, guess what the odds are of them changing their behavior when the chips are down? Right. It's likely to get even worse. So guess what they're going to do when you need them most?
Let you down. It doesn't matter how much effort you've put into them, they will let you down. The sad thing is that almost anything else you might have done short of self-mutilation would have been a better use of the time.
People need to be taken as a whole. You can't just pick out one or two parts you like and figure you can work on the rest. That's a simultaneous application of optimistic probability bias and requisite of personal responsibility, and it's a waste of time.