Bayern Munich fans are not happy. Despite brushing Borussia Dortmund aside 2-0 for the DFB Supercup and trouncing Werder Bremen 6-0 in their opening Bundesliga match, the Bavarians are seething.
And the mercurial Arjen Robben is the object of their ire. They forgave him for his 2012 Champions League final performance, all the missed chances, the feigning injury and THAT slap on Thomas Muller. But sending his son, Luka, to train with arch rivals 1860 Munich? Not a chance.

(Image courtesy of 101greatgoals).
The Netherlands international was pictured watching his son train with the 'enemy', seemingly enjoying himself and the Bayern fans took to the internet to let him know just what they thought of his treachery.
They didn't stop there, however. Bundesliga fans do not do half measures and to make sure Robben fully understood his transgressions, they unfurled a giant banner during the Werder Bremen match, which read: "There's only one team in Munich, Arjen!"

The former Chelsea superstar, 33, wasn't playing due to an injury he sustained during pre-season but we're sure he got the message!
Robben isn't the first famous father to send his son into enemy territory as Manchester United legend Andy Cole allowed his son, Devante, to join City, while Peter Schmeichel agreed to allow his son, Kasper, to don the sky blue jersey too.