It's official: Hilary Duff is tying the knot.
After a years-long romance, the Younger star and her longtime love, musician Matthew Koma, are engaged. The couple shared the big news on social media, Duff writing to fans, "He asked me to be his wife" along with a photo showing off a new sparkler. According to Ira Weissman, founder of The Diamond Pro, the ring features a cushion cut solitaire diamond that appears to be around five to six carats and could be worth upwards of $200,000. Andrew Brown, CEO of WP Diamonds, estimated the jewel to be around four carats with a price tag around $100,000.
"Matthew really wanted to throw Hilary off guard and wanted it to be a complete surprise. She had no idea it was coming," a source told E! News of the proposal. "Matthew surprised Hilary one night after filming. It was just the two of them on a rooftop outside. Matthew wanted it to be meaningful, but casual because he knows Hilary wasn't dying to get engaged. She knew it was important to him and he wanted to propose to signify them being a family unit."
Such marks the latest milestone in the couple's romantic history, beginning with a 2017 red carpet debut with breakups and makeups mixed in. Last fall, the pair welcomed their first child together, daughter Banks, making them a family of four with Duff's son, Luca Comrie.
While a future engagement was less certain, "Hilary has always known she would be with Matthew forever and having Banks sealed the deal," the source added. "She's really happy and excited. Everyone in Hilary's family has always loved him and seeing him be a dad to Banks now has only made their relationship stronger."
Take a walk back through their relationship so far with E!'s gallery below: