The 34-year-old model and television personality and 41-year-old singer discussed on Tuesday's episode of Good Morning America how the death of their son Jack has brought them closer together.
Teigen experienced a pregnancy loss in September while 20 weeks pregnant with her third child with Legend, a boy they named Jack. On GMA, Teigen and Legend shared the "utter grief" they felt after the loss.
"I definitely give myself permission to feel complete and utter grief," Teigen said. "Every day is so different. So when people ask me how I'm doing I always say I'm okay -- today."
"I didn't know that we could experience this grief and also share it, but when we did it really meant so much to so many people," Legend added. "And it was such a powerful experience for me to learn that."
Legend said the loss has strengthened his bond with Teigen.
"I just know that I love my wife, more than ever," the singer said. "We've been through so many challenges together and they've made her stronger, and I know that doesn't always happen when people go through tragedy."
"I feel like the challenges we faced together have made us feel even more sure about who we are together as a couple and who we are as a family," he added. "I feel like we're stronger together than we've ever been."
In addition, Teigen and Legend promoted Ronald McDonald House Charities' new initiative #HereForRMHC, which provides resources to and assists families with sick or injured children in the hospital.
Teigen and Legend married in September 2013 and have two children, daughter Luna, 4, and son Miles, 2. Legend performed "Wild," a "passionate" song inspired by his marriage, on Late Night with Seth Meyers this month.