Just like the McDonalds cheeseburger it looks and sounds good, but you alway wonder 'why did I eat that, it was nowhere near as good as it looked. ' Its that one chick that everyone wants. Only after you sleep with her you wonder, 'Why did that seem like a good idea, she was totally disappointing!'
Steve: 'Dude, that chick you took home from the church picnic was so hot'
Tom: 'Man, she turned out to be a McDouble'