Crystal Harris: Cheating on Hugh Hefner With Jordan McGraw?

Is Crystal Harris cheating on fiance Hugh Hefner with Jordan McGraw, son of that blowhard Dr. Phil? What could possibly trigger such a ridiculous rumor?

The fact that she's 24 and Hugh is 84, possibly? Just an idea.

Reports say the lovebirds (Crystal and Jordan) were cozy at the Chateau Marmont in LA on March 14 and that she's "trying to keep the romance low-key."

Too bad "Jordan didn't hide his affections, kissing her shoulder and trying to hold Crystal Harris' hand - still adorned with a 6-carat engagement ring."

Jordan McGraw is the younger of that bloviating windbag Dr. Phil's two sons. The older one, Jay, is married to Playboy model Erica Dahm, interestingly.

But anyway. Jordan and Crystal "are sneaking around because Crystal is supposed to be happily engaged to Hef," a source tells Life & Style.

"Going out in public with Jordan would tarnish Hef and Crystal's image."

We don't really see how. She's obviously going not dating Hef for his virility. Just putting that out there. Will they even make it to the altar?

June 18 is the wedding date. A Playboy representative says Jordan and Crystal's relationship is strictly business ... the business of BONING!

Just kidding. Well, probably. Really we wouldn't be surprised either way.