British thing, chav culture from about a year ago. Rio Ferdinand went around attempting to "merk" fellow members of the England football squad, and laughed that line in their faces regardless of how affected they were. For example, he convinced Wayne Rooney that he'd killed a kid's dog, and Rooney responded, whilst walking away, "Well... sorry mate, it weren't my fault." Not quite what was intended.
He also make Beckham think he was being kidnapped, and make him jump out of a moving vehicle a few weeks before an important match.