Lady Gaga had a specific way of keeping in character on Joker 2 set

gamesradar.com:

Lady Gaga had a specific request on the Joker 2 set – and it seems like a way of keeping in character as Harley Quinn. 

The actor, who was born Stefani Germanotta, also stayed in character while filming House of Gucci. 

"I didn't know Stefani at all," Joker 2's director of photography Lawrence Sher said in an interview with The Trenches TALK podcast. "And strangely, I felt like I never really even met her, even during the makeup/hair tests. Because again, maybe it was my philosophy of not trying to get in their space – and then I remember for a week, being like, 'God, I feel like we're disconnecting. Not even connecting. We're on opposites.' And I would say to my crew, 'Jesus, I can't crack it. I feel like she either hates me or we hate each other. There's something weird going on here.' And I barely said anything, except I would say like, 'Stefani, this is where your second team was,' whatever it was, minor little things."

One request passed on to Sher, though, changed everything. "And then the AD at one point said, 'Oh you know, Stef would like if you just called her Lee on set.' And I was like, 'Oh, 100 percent,' and then I literally said, the next thing I said, was something 'Lee,' and it was like everything changed. From that point on, it was like – our whole connection changed. I was like, 'Well, alright, cool, that's all I need to know,' and that changed everything."

It's not totally clear why the Lee nickname was preferred, but we're going to guess it's a shortened version of Harley (or Harley's real name, Harleen). The film, officially titled Joker: Folie à Deux, looks set to focus on Harley and Joker's relationship. It's also a musical, and set videos of Gaga singing have hit the internet. 

Set photos have also