Bruce Willis got "stuck" in Idaho so had to quarantine with his ex-wife Demi Moore.
The 'Die Hard' actor still has a good relationship with his former spouse so has been staying with her and their three daughters Rumer, 31, Scout, 28, and 26-year-old Tallulah, during the coronavirus pandemic, while his wife Emma Heming is in Los Angeles with their two kids, Mabel, eight, and Evelyn, five.
An insider explained Bruce's entire family originally planned to join him until there was an outbreak of the virus in the area.
The source explained: "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 65-year-old actor - who split from Demi in 2000 after 13 years of marriage - is in touch with Emma and their kids "daily" and none of them are finding the unusual domestic set up particularly "weird".
The insider told 'Entertainment Tonight': "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 socialising with anyone but their family.
"Bruce isn't with his wife or young children, but that was understood going into this.
"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."
While Bruce and Demi "never thought they would be forced at this age to stay in one home together 24/7", they are having a lot of fun with their daughters.
A source said: "It's become a slumber party and they have settled in perfectly.
"Emma loves Bruce and is fine with him staying with his older children and Demi during this time."