"I tend to go from marriage to marriage -- leaving one wife for another," Foster told the magazine. "This is the first time in my adult life that I've been single. It's a very powerful feeling, but I'm not used to it."
"Someone said to me recently that you need to be very careful about the person you pick to spend the rest of your life with," he said.
"It's kind of weird that I'm hearing that now and thinking, 'Oh, right.'"
Foster was previously married to singer B.J. Cook, Rebecca Dyer and actress Linda Thompson.
He and Foster, who was wed to Mohamed Hadid, split in December 2015 after four years of marriage and nine years together.
"Sadly we have decided to go our separate ways," the pair said in a joint statement at the time.
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"We've shared nine beautiful and joyous years together. During that time we experienced love, friendship and the inevitable challenges that come with managing a marriage, careers, blended families and health issues," they added.
Foster is dad to daughter Allison from a past relationship, daughter Amy with Cook, and daughters Sara, Erin and Jordan with Dyer, while Hadid is mom to daughters Gigi and Bella and son Anwar with Mohamed Hadid.
Sara and Erin predicted on "On Air with Ryan Seacrest" in July that their dad would marry again.
"We just want him to be happy," Erin said.
"We love when he is married, in a relationship. He is at his happiest when he is in a relationship. He will definitely get married again. He loves being married. Lucky No. 5!"
Foster and supermodel Christie Brinkley were linked in December after being spotted on dates in New York.
Sources told Us Weekly at the time that the pair were "hitting it off."
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