London: Kate Moss reportedly told Justin Bieber to behave himself and be more respectful recently.

Kate Moss and Justin Bieber
Kate Moss and Justin Bieber. Pics/Santa Banta 

According to the source, it was during director Riccardo Tisci's 40th birthday bash, when the supermodel, 40, was heard giving the 20-year-old pop brat some 'choice words' like a teacher, after he tried to greet her in a cocky manner, the Daily Star reported.

The source further revealed that the 'Baby' singer was left speechless after the "slap in his face" kind of incident.