Joan Rivers doesn’t think Lady Gaga grasps the humour of her show.

The 26-year-old songstress wrote an open letter to Joan’s Fashion Police co-host Kelly Osbourne last week, calling for her to be a better role model.

Gaga invited Kelly to be more positive while critiquing people on the programme, as the singer currently believes the show “breeds negativity”.

Comedy legend Joan is amazed by the conversation that’s transpired.

“If you're going to say someone's a bully, say it to their face,” the comedienne told Extra.

“[Gaga] doesn't understand the humour of our show. This is a woman who dresses in meat, you know what I’m saying?”

The feud began after the Fashion Police TV presenter poked fun of Gaga for wearing a burka at London Fashion Week during an appearance on UK television show Alan Carr: Chatty Man.

Gaga’s fans inundated Kelly with cruel taunts and death threats.

Sharon got involved and wrote Gaga’s manager an email asking him to step in.

In response to Sharon’s request, Gaga wrote an open letter to Kelly, but later took down the post from her website.

Sharon then wrote a message on her Facebook page, calling the pop star a “hypocrite”.