|1.||high school girlfriend|
A disease that afflicts college freshman, mostly straight men. Its counterpart, high school boyfriend, is not as common. In a typical case, the HSG-sufferer is devoted to what he believes is the love of his life, a high school junior or senior in his hometown (several hundred/thousand miles away). He'd rather stay in his dorm room skyping with her than meet any new friends, and when she comes to visit, his roommate can expect to be sexiled for whole weekends at a time.
This will go on (and on, and on) until their relationship explodes--hopefully at Thanksgiving during the turkey drop, but it can take until sophomore year in extreme cases.
Tom: Did you ask your roommate if he wanted to go to that party tonight?
Dan: No, I give up. He's got the worst case of high school girlfriend I've ever seen.
Lisa: Hey, Dan's roommate's pretty cute. Why doesn't he ever want to hang out?
Emily: High school girlfriend strikes again.
Lisa: Oh, no! When will they find a cure?