Hugh Hefner may be 84 years old but he is showing no signs of slowing down anytime soon. Hefner got engaged to his girlfriend, Crystal Harris, 24, for Christmas.

Hefner tweeted about it saying,

"After the movie tonight, Crystal & I exchanged gifts. I gave Crystal a ring. A truly memorable Christmas Eve." He later tweeted, "When I gave Crystal the ring, she burst into tears. This is the happiest Christmas weekend in memory."

A Playboy rep confirmed the engagement to UsMagazine.com.

This will be Hefner's third marriage and Crystal's first marriage.

Hefner was dating Holly Madison, one of his co-stars on Girls Next Door, but broke up last year because he didn't want to get married and Madison did.

What do you think about Hef getting engaged??