4thie means your is your 4th bestie in the boy/girlfriend spot, because MSP won't let you have more than 3 best friends on your profile.
ex: putting your best friend in the bf/gf spot. This doesn't mean you are dating.
A person you hate intensely not because they deserve such hatred but because they serve as a focus for your general hatred. A healthy way to dispense with excess animosity.
Jake's not really that big an asshole. He just serves as my hate sink.