Robert De Niro has been a leading actor in several films. However, he also knows how to take on a supportive role—including in his personal life. 

His girlfriend Tiffany Chen recently shared how the two-time Oscar winner helped her after she was diagnosed with Bell's palsy, a condition that impacts facial muscles.

"He was very sweet," the martial artist told Gayle King on CBS Mornings July 13. "He tried to say that he didn't see any difference, he didn't see any change. He was like, 'No…You look fine. Maybe you look a little stern.' And I'm like, 'Really? My whole face is melted on itself.' But he was very strong, very supportive."

Chen started noticing symptoms shortly after giving birth to her and De Niro's first child together, a baby girl named Gia Virginia Chen De Niro, in April—noting she experienced a "sharp pain" behind her left ear while she was in the delivery room. While doctors initially assumed it was fluid build-up, the athlete became more concerned as time went on.

"When I finally could shower, I remember looking at myself in the mirror and saying, 'Something definitely is looking odder.' But it was all in the eyes. And I said, 'Well maybe I'm just off because I have so many meds pumped into me,'" Chen remembered about that time after giving birth via C-section. "When I get home, it was like everything was starting to just fall down on itself. Like, my face was melting on itself. And then a week after giving birth, that was when it all hit."

According to CBS Mornings, she then called her doctor and was admitted to the hospital, with her recalling how she "lost all facial function the minute" she got there. The outlet noted an MRI then led to the diagnosis.

Chen told King she treated the condition with steroids and acupuncture. However, she acknowledged that going through this health struggle in the public eye hasn't been easy and revealed whether she ever feels self-conscious.

"I am and then I'm not," the champion—who's attended red carpet events and been photographed by paparazzi with De Niro—shared. "I've never really cared too much about what I look like. But what bothered me is that I couldn't smile at the baby at the beginning, and I couldn't give her kisses. That's what made me self-conscious. And then we decided we're going to live our life and be social."

And Chen noted that the way the Raging Bull star—who she said she started dating years after they worked together on the 2015 film The Intern—cares for his loved ones is one of her favorite things about him.

It's "how much he loves his family," she said about De Niro, who also has six children from previous relationships. "That might make me a little teary-eyed."