Pronounced "four-nine-two", this is how a friend of mine describes the "beer goggles effect" that occurs when you end up sleeping with an unattractive girl when drunk. The numbers refer to the marks out of 10 given to a girl based on her looks.

Before you take a drink, the girl in question is marked 4\10 for hotness (i.e. not passable)

When you're drunk and doing the dirty deed, she's a nine.

The next morning, she's a 2, mostly because you can remember what she looked like naked.