"I got a beautiful ring from my boyfriend for my birthday last weekend," Reid, 34, tells PEOPLE exclusively. "But we're not engaged ... yet!"
The actress and Axtmann, an Internet entrepreneur, began dating earlier this year. Along with her decision to pose nude for Playboy for its January/February '10 double issue, her life's been on an upswing since she entered rehab last year.
She says posing sans clothes was liberating.
"Playboy had approached me in the past, but now just seemed like the right time to do it since I'm in a great place in my life and in love," she says. "I felt incredibly comfortable at the shoot. I think it helped a lot by choosing a brilliant female photographer."
The magazine's cover and nude pictorial, which hits newsstands Dec. 18, was shot outdoors in October at an estate in Los Angeles.
"It also helped that the first day was for the cover, which is not nude!" Reid adds. "So I had a whole day shooting with this crew and that helped make me comfortable for the second day, which was a closed set."
The actress also recently completed production on the comedy Last Call and the psychological thriller The Fields.