Mills' lengthy post came after reports the couple had gone their separate ways on Wednesday.
The couple's last red carpet appearance together was in October.
Nielson and Randone announced their split on Friday, less than a year after their June 2019 wedding.
The singer confirmed the news amid recent breakup rumors.
The actress shared the news on her podcast earlier this month.
The two tied the knot on Jan. 20 in Malibu.
ET chatted with Sandra Lee at the Recording Academy and Clive Davis' pre-GRAMMY gala over the weekend.
The two broke up in 2019, after four years together, during which they welcomed now 4-year-old daughter, Lea.
Giudice took to Instagram to reflect on his separation from the 'Real Housewives of New Jersey' star.
Fans began to worry about Star after reading a couple of his social media posts.
ET's Katie Krause speaks with Jake Paul about his break from Tana Mongeau and if they plan to get back together.
Cyrus got engaged in December of 2018.
The 'Conners' star and the former 4 Non Blondes singer tied the knot in May 2014.
The pair split up in August after seven months of marriage.
