If you ask your mates to choose a fun fancy dress outfit and you're a man, you can probably expect that a blond wig will feature in there somewhere.
Which is exactly what happened to Max Newton, a Nottingham Forest fan who wanted a costume for the Great North Run, the Nottingham Post reports.
He asked for suggestions and before long, mischievous friends had begun forwarding requests for him to dress up in a Derby County strip, which then turned into people asking him to dress up as Robbie Savage, an arch enemy of all Forest fans.
Max bravely accepted and will soon do the run for charity, wearing a wig, a Derby County football shirt and a mask with Robbie's face on.
"It will be a horrible, humiliating experience. I expect to be roundly booed and jeered by those lining the route," he joked.
Robbie has seen the costume himself and is reported to be thoroughly amused - although he did say Max hasn't got his style.
If you've got a pal daft enough to let you choose his costume, may we recommend a female cheerleader fancy dress outfit for maximum embarrassment?