When you walk into a seemingly normal restaurant in
Thailand or
Cambodia, a bunch of girls will come swarming around your table, wearing sashes of different kinds of beer (
Angkor Beer,
Singha Beer,
San Miguel, etc.). They offer you a beer, and you choose one innocently. You thought you were choosing a beer, but actually you were choosing a girl. She gets very happy, and the rest frown and walk off. For the rest of the meal, the girl of your beer will come around, trying to get you to buy more beer and refilling your glass.
If you decide to switch beers in the middle of a meal, they won't be happy.