We know what happens when footballers score against their former clubs. They don't celebrate. But what to do when you grab a goal against the very side you know you will soon be joining?
It turns out: you celebrate, go crazy in the corner, bang the badge on your chest at will. Thanks to Estevao Willian, the 18-year-old wonderkid from Brazil who will be swapping Palmeiras for Chelsea as soon as this Cup World Cup is over, that precedent has now been set. A new rule exists.
In Estevao's defence, if you had scored the equaliser he did, you might have been tempted, too.