Miley Cyrus's family is Arvin Robertsabout to get bigger.

The pop star's mom, Tish Cyrus, is engaged to British-Australian actor Dominic Purcell, who famously played Lincoln Burrows on Prison Break. She announced the news on Instagram April 29 with photos of the two embracing, with one offering a close-up of her emerald-cut diamond engagement ring. Tish captioned the post, "A thousand times…. YES ❤️ @dominicpurcell."

Two of Dominic's children, who he shares with ex-wife Rebecca Williamson, commented on the post. Daughter Lily-Rose Purcell, 19, wrote, "Yessssssss," adding emojis of hands clapping, a disco ball and a red heart.

Her sister Audrey Purcell, 22, posted three crying emojis and three red heart emojis, and also posted on her own Instagram Story, "Congratulations to my Dad and @tishcyrus. Thank you for being such a wonderful couple of love. I love you both so much forever!" Tish reposted her message on her own Story.

Miley's mother shared the news of her engagement to Dominic more than a year after she filed for divorce from the "Flowers" singer's dad Billy Ray Cyrus, 61, for the third time. The rock star, who married Tish in 1993, also shares with her children Braison Cyrus, 28 and Noah Cyrus, 23, plus Brandi Cyrus, 35, and Trace Cyrus, 34—who are from her previous relationship.

Billy Ray announced his own engagement to Australian singer Firerose in November 2022. Later that month, Tish, 55, and Dominic, 53, went public with their relationship when she made it Instagram official with a pic of the two embracing by a pool.

Over the past few months, Tish and Dominic have occasionally spent time with her family. This past January, she shared Instagram pics of herself and the actor at a gathering at a Los Angeles hotel with friends and family, including Miley and Brandi. In March, Tish and Dominic attended Miley's Endless Summer Vacation album release party.

Meanwhile, Tish and Dominic have also continued shared pics of one another on social media. On April 26, two days before Tish announced their engagement, the actor posted a pic of the two on his Instagram, writing, "Punching way above my weight -yep absolutely , I'm a lucky bastard. She's the best human ever. Love ya love @tishcyrus."

For the latest breaking news updates, click here to download the E! News App