WATCH: Ronaldo should know better than to mess with Pepe

For every action there is an equal, opposite and shameless reaction. This is one of the fundamental rules for Real Madrid's defender Pepe.

Almost everyone who has faced Pepe knows this, and you would think Cristiano Ronaldo, who plays with Pepe on the Portuguese national team as well as at Real Madrid, would know definitely know this.

Well, guess again.

In a practice session during Real Madrid's preseason tour in Australia, Ronaldo bumped Pepe with his chest. What does Pepe do next?

Pepe does what he always does. Take a look:

Ronaldo, there is a reason why Pepe's nickname is "The Assassin" and you would be wise to never forget that. The Pepe does not discriminate.