Leonardo DiCaprio once gave stern warning to co-star who was fooling around on set

Leonardo DiCaprio has what industry observers say is a multi-fold of experience in performing in films.

He is quite aware of the 'dos and don'ts,' and the advice he gives related to filmmaking reportedly must be taken seriously.

Claire Danes had one such piece of advice during the shooting of 1996's Romeo + Juliet.

She starred next to the actor in the romantic drama.

On set, the pair had been preparing for an emotionally intense scene.

It was the scene about the tragic suicide of Juliet.

At the time, the actress was 17, so, in the joy of youth, she tried to lighten the mood — before the scene — by playing with a prop gun.

"I remember just blithely playing with the prop gun and putting it to my head," Danes recounted in a Variety interview.

DiCaprio, in an instant, gave her a stern warning not to toy around with a prop gun.

"And Leo getting very serious and saying, ‘Claire, we don’t do that. Don’t eff around.’”

Danes heeded DiCaprio's warning and stated, “He was right, but I was just being a doofus and a girl.”

It is worth noting that Hollywood appeared to have taken an extra precaution with prop guns after the tragic incident at the shooting of Rust in 2021.