"I'm so scared to be bad. I don't want to be bad," the "In My Blood" singer said

Shawn Mendes is always striving to be the best version of himself.

While appearing on the Man Enough podcast Monday, the 22-year-old singer spoke openly about his worries of being the bad guy in his relationship with girlfriend Camila Cabello.

When asked by co-host Justin Baldoni what "terrifies" him most, Mendes recalled how he saw himself following a recent argument with Cabello, 24.

"I raised my voice at her and she was like, 'I don't like it when you raise your voice. Why did you raise your voice?' And I got so defensive," he said. "I was like, 'I wasn't raising my voice at you!' And I did raise my voice at her. And then I felt her shrink and I felt me grow and I was like, 'Oh God, this is the worst.' "

"I'm so terrified of being evil. I'm so scared to be bad," the "In My Blood" singer said. "I don't want to be bad."

Camila Cabello and Shawn Mendes
Camila Cabello and Shawn Mendes
| Credit: Kevin Mazur/AMA2019/Getty Images

Mendes then explained that he and his sweetheart "had to get in this massive conversation" about what went down during the spat.

"Maybe there even is bad inside of me, and I have to just accept that that exists," the singer said. "And that other part of me, he's just got to be here and we've just got to work together until eventually he gets worked in all of the trauma and all of the kinks get rubbed out of him and he's okay."

"But I can't avoid the fact that there's a little bit of darkness inside of me," Mendes continued. "And letting that darkness kind of be present is a horrible feeling."

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Shawn Mendes, Camilla Cabello
Camila Cabello and Shawn Mendes
| Credit: John Shearer/Getty

The "Stitches" singer added that Cabello knew just what to say after he got defensive.

"I made it about my evil and my fear, and she comforted me," he recalled. "And then it took me like 20 minutes of us separately reading our books to be able to come back to her and be like, 'God, that was a whole thing and I'm really sorry.' "

"... You think you're being vulnerable and saying the right thing, but you're really just defending yourself even better," Mendes said of the emotions.

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The "Señorita" singers have been friends since 2014, and went public with their relationship in July 2019.

In December, Mendes told PEOPLE that things are getting more serious, revealing he and Cabello have even talked about getting engaged.

"I don't know why, but I just know that she is," Mendes told PEOPLE about knowing his girlfriend is "the one."

"I think that your person really just has to be your best friend, and she has been that for so many years now," he said of the "Havana" singer. "She is so unapologetically diving into love, and she really taught me what it is to be vulnerable and honest and true in a relationship."

"She's really so brave and courageous in love," Mendes added. "I'm constantly learning from her."