The 26-year-old designer gushed that the lovebirds are inseprable now, reported Hello! magazine.
"Do I believe in love at first sight? I didn't before Ruby but now I do. I have to! It happened to me. I met Ruby at a barbecue I threw a year and a half ago and we got engaged within about three months. It was all very instant... Honestly, we're not really apart that often," Dahl said.
"We're enjoying being engaged. Ruby wants a low-key wedding but I want a big one. I'm from a family of 50 so it's going to have to be big. I don't know how anyone has time to plan a wedding, we're both so focused on our careers right now," she said.
Rose, 29, is a representative of LGBT rights and the couple also plan to use theior celebrity status to support the issue.