On-screen regular couple Bradley Cooper and Jennifer Lawrence have been in four films together, but did romance ever spark between the two?

The "American Sniper" actor guested on the Howard Stern's show on Sirius radio and the funnyman asked, "Bradley, what is going on there? Jennifer Lawrence. You're doing another movie with her. Is she becoming the woman you have the most chemistry with? What is going on?"

Bradley Cooper answered, "It's due to David O. Russell, that's what's happening," referring to the director. "We did Silver Linings Playbook together. We got along great."

However, they never dated because the romance "just didn't happen."

"It's not the way we are together," he said.

Previously, Bradley Cooper was quoted as saying that he would never date Jennifer Lawrence because of the 15-year age gap.

"I said that once on a red carpet just as a diffuse thing," he clarified. "And then it became a thing because the girl I was seeing [Suki Waterhouse, 23] was as young as she was."

Bradley Cooper broke up with model Suki Waterhouse over the summer and moved on to Irina Shayk. Jennifer Lawrence, meanwhile, was rumored to have an on-and-off relationship with Coldplay frontman Chris Martin following his divorce from Gwyneth Paltrow.

In an interview with Us Weekly, Bradley Cooper insisted he's not dating Jennifer Lawrence.

"Honestly, it's just happenstance," he said. "We both got cast in Silver Linings, and she was going to this other movie and the role was open and so that worked out "I respect her so much as a professional, as an actor, and I think she's the best there is."

"I just learn from her," he added. "You always want to work with people who are better than you."

Jennifer Lawrence also said in the same interview that she feels the same way about Bradley Cooper but she assured that there's "no sex" in their relationship.