The 38-year-old singer said in an interview with The Guardian published Sunday that Teigen refused to let him end their relationship.
"I was really stressed and busy," he explained. "I was just like: 'I'd be happier single right now,' and she was like: 'No.'"
Legend said he and Teigen got back together less than a half hour after their conversation. The couple went on to marry in Como, Italy, in 2013, and welcomed their first child, daughter Luna, in April 2016.
"She pushes me to be funnier," Legend lauded of Teigen, "not because she's trying to, I think it's just being around her. And to be bolder."
Legend told Cosmopolitan in August that having Luna strengthened his bond with Teigen. The pair conceived Luna via in vitro fertilization after struggling with fertility issues, and plan to have more children in the future.
"Having a baby is a big challenge for a couple, and going through that together strengthens your bond because if you make it through [having a child], you know you can make it through anything," Legend told the magazine.
"I wouldn't say we can't conceive naturally, but I would say that it's enough of a challenge where it felt like we needed help," he said. "We're lucky that we're living in an age where we can conceive in other ways. [IVF] brought us Luna and hopefully it will bring us a few more awesome kids, too."