Hugh Hefner and his No. 1 girlfriend Holly Madison are apparently trying to reproduce like a Playboy bunny.

"There has been lots of trying -- lots of trying!" Madison told Us Weekly at Playboy's Ninth Annual Super Saturday Night party in Arizona.

The 81-year-old founder and editor-in-chief of Playboy and the 27-year-old Madison -- who co-star in E!'s The Girls Next Door reality series along with fellow girlfriends Bridget Marquardt and Kendra Wilkinson -- have reportedly been discussing marriage for almost a year now.  However Hefner doesn't seem too eager to tie the knot for a third time.

"There will certainly be a lot of romantic years ahead, but a wedding we will see," he told Us.

Considering his old age, Hefner presumably takes his relationship with Madison one day at a time, meaning next up is Valentine's Day.

"We are just going out to dinner," Madison told Us. "I am trying to think of something creative, but at this point I am just going to save all of my ideas for Christmas cause Valentine's Day came up fast."

Madison moved into the Playboy Mansion in 2001 and over the years gradually became Hefner's "No. 1 girlfriend."  During an April 2006 interview with Alan Colmes, Hefner stated that Madison was the true "love of his life." On episodes of The Girls Next Door, Madison has said she wants children with Hefner and often gives him hints.

"I want like a house and a kid," Madison told Us about gift ideas from Hef, a somewhat odd statement considering she already sleeps in the same bed as him at the massive Los Angeles-based mansion.

The Girls Next Door premiered on E! in August 2005 and is currently airing its fourth season on Sundays at 10PM ET/PT.