Football rivalries run deep in families, and the same goes for a family pet, like this Spanish dog, that’s probably been taught to look calm and docile when hearing the names of Real Madrid players, but turns into a vicious attack mutt when he hears names of Barcelona players.

The owner of the dog is obviously a Real Madrid fan, who taught his dog to show his teeth when he hears names like Lionel Messi and Sergi Busquets, while looking all happy and quiet when the names of Cristiano Ronaldo and Sergio Ramos come up.

Maybe it isn’t something he was taught. Maybe he is simply reacting to watching his family act during La Liga matches, and specifically against Barcelona when there’s an El Clasico.

Hate sometimes is difficult to explain, especially when it comes to sports. Sometimes it is more ferocious than the actual love one feels for his team. This dog seems to be no different: He doesn’t care, almost indifferent, when hearing the names of players from the team he supports. He gets all insane when the names of Messi and Busquets, players he was taught or learned himself to hate, come up.