The two were spotted shopping for engagement rings yesterday at Jacob and Co., where they examined an array of baubles, including a 30-carat rare blue diamond, reports the New York Post.
The couple couldn't decide on a ring, but Paris bought one anyway.
She walked out sporting a black diamond-encrusted ring worth 25,000 dollars for her 30th birthday.
Hilton celebrated with Charlie Sheen's ex, Denise Richards, at Asellina on Thursday.
Later at Lavo, Paris said that she looks forward to being engaged.
"We've talked about it," she said. "This is once in a lifetime. I want to be with him forever."
