The soap star and his long-term girlfriend, who have two children together, were enjoying a romantic break in the Lake District to celebrate their 10-year anniversary when Chris popped the question.
Speaking exclusively to OK! magazine, Chris and Rowena opened up about the romantic proposal (and how it all nearly ended in disaster!).
The couple were exploring a waterfall the day after their anniversary in the Lake Disctict, as it was where they'd had their first trip away together.
Chris recalled: 'We'd seen an elderly couple walking and holding hands earlier. It was very sweet. I said to Row, "There's a reason I brought you here. You know that old couple we saw earlier? Well, would you like to grow old like that with me?"'
The actor revealed the news of their engagement on Twitter, captioning a pic he posted: 'Finally, I popped the question to @row_finn and...'
The photo showed some Scrabble pieces that spelt out 'she said yes'. Aww!
When asked how they feel since getting engaged Rowena, 33, said: 'I think getting married will bring us even closer together,' while, Chris, 44, added: 'I feel a different sort of closeness because wherever Row goes I know she's wearing her engagement ring.
'It's nice to know it's on her finger and she's coming back.'
Despite being together for 10 years, mum Rowena said the proposal still came as a shock: 'All my friends said it was obvious Chris was going to propose after ten years, but to me it wasn't because I'd already waited ten years!' she said. 'Every anniversary I was always hoping I'd get a ring.
'I was in shock. The ring blew me away. Then I thought, let's get off this ledge! I finally said yes and the ring fitted perfectly. It was amazing. We both got a little emotional.'
Chris revealed he didn't get down on one knee due to 'health and safety reasons', adding 'I was also worried about dropping the ring in the water because my hand was shaking.'
The couple have a three-year-old son, Harry, and an 11-month-old daughter, Ella Rose.
Read the full story in this week's OK! Magazine - out today