The Die Hard actor gets along great with both Heming and his ex-wife, Demi Moore, whom he's currently quarantining with alongside the actors' children: Rumer, 31, Scout, 28, and Tallulah, 26. As for why Willis has been self-isolating with Moore and their kids in Sun Valley instead of his current wife and their young children in Los Angeles, a source tells ET that Willis kind of got stuck in Idaho amid the coronavirus outbreak.
"He has a house directly across the street from Demi's house in Sun Valley. It's been for sale for years. He was visiting and his family was considering quarantining there. He got stuck because Sun Valley became one of the COVID-19 hotspots," the source explains.
As for Heming, she was OK with Willis staying in Idaho as she prefers sunny L.A. "He's very much with Emma," the source adds.
A second source tells ET that Willis is in touch with Heming and their daughters -- Mabel, 8, and Evelyn, 5 -- "daily," and that them being apart isn't "weird to them."
"Bruce and Demi made a decision to quarantine together with their children and have been doing so for over a month. The family didn't want to take any risks of outside influences so they've stayed away from socializing with anyone but their family. Bruce isn't with his wife or young children, but that was understood going into this," the source shares. "Bruce, Demi and Emma have always had a great relationship and are good friends and none of this is weird to them. It's outside people who are making it more than it is."
Moore and Willis divorced in 2000, after 13 years of marriage. While they've been close friends for years, a third source tells ET they "never thought they would be forced at this age to stay in one home together 24/7."
That doesn't mean the former couple aren't enjoying their time together, however. "It's become a slumber party and they have settled in perfectly," the source says, repeating, "Emma loves Bruce and is fine with him staying with his older children and Demi during this time."
See more on how Willis has been spending his days during quarantine in the video below.
Reporting by Adriane Schwartz.