Wow... Hard to believe but there're still plenty of places in the States where you could be fined and thrown to jail for living with your boyfriend/girlfriend. Or you could lose your job (via Jane Keeler):

There are some 144,000 unmarried couples living together in North Carolina, and they are all breaking the law - a statute that has been on the books since 1805.

The law against cohabitation is rarely enforced. But now the American Civil Liberties Union is suing to overturn it altogether, on behalf of a former sheriff's dispatcher who says she had to quit her job because she wouldn't marry her live-in boyfriend.

Deborah Hobbs, 40, says her boss, Sheriff Carson Smith of Pender County, near Wilmington, told her to get married, move out or find another job after he found out she and her boyfriend had been living together for three years. The couple did not want to get married, so Hobbs quit.

[...]

North Carolina is one of seven states that still have laws on the books prohibiting cohabitation of unmarried couples. The others are Virginia, West Virginia, Florida, Michigan, Mississippi and North Dakota. North Carolina appears to be the only state where the law is being challenged. [...]