United Kingdom, May 3 -- Crystal Hefner's new fiance admitted keeping his proposal planning a secret was difficult.

James Ward, 41 - who started dating Crystal, 39, last year after meeting through mutual friends - admitted the pair never keep secrets from each other so working on a surprise proposal was tough.

He told PEOPLE: "It runs so contrary to our connection to keep anything from her [but] there was just that small buoying force of knowing how happy the surprise would make her that made it so worthwhile.

"If you know Crystal, you know she doesn't miss a thing. She's that wonderful combination of smart and attentive, so I really had to step up my game to avoid an overshare. I also had a LOT of help from a whole host of people that...