Hugh Hefner and Crystal Harris

Hugh Hefner gave his girlfriend a pretty good Christmas gift.

The 84-year-old Playboy founder proposed to his 24-year-old girlfriend, Crystal Harris Friday night. "I gave Crystal a ring. A truly memorable Christmas Eve," Hefner  tweeted. "When I gave Crystal the ring, she burst into tears. This is the happiest Christmas weekend in memory."

Hefner later clarified that he did indeed ask Harris to marry him. "Yes, the ring I gave Crystal is an engagement ring," he wrote. "I didn't mean to make a mystery out of it. A very merry Christmas to all."

See who else got engaged in 2010

Harris was the December 2009 Playboy Playmate. She started dating Hefner a month later. The couple's relationship was part of the focus of Season 6 of the E! reality series, The Girls Next Door.

This will be the third marriage for Hefner. In 2009 he filed for divorce from his second wife, former Playmate Kimberly Conrad, after the two separated in 1998. Together they have two sons. Hefner and his first wife, Mildred Williams; divorced in 1959. They also have two children.