the reason they eventually break up is that quinn is too jealous of casper's perfect hair every morning and she just can't stand it anymore.
a cabin probably burns down in the process.
ETA: their relationship is labeled a Weapon of Mass Destruction by the DOD. the government planted the "your hair is too perfect" idea in quinn's head.
when they break up, this is also a contributor to how quinn and robin get together; she spills her suspicions about the government's involvement to robin, and he finally found someone that understands his (anti-)political views.
Re: Katie
the reason they eventually break up is that quinn is too jealous of casper's perfect hair every morning and she just can't stand it anymore.
a cabin probably burns down in the process.
ETA: their relationship is labeled a Weapon of Mass Destruction by the DOD. the government planted the "your hair is too perfect" idea in quinn's head.
when they break up, this is also a contributor to how quinn and robin get together; she spills her suspicions about the government's involvement to robin, and he finally found someone that understands his (anti-)political views.