HARRY CONNICK JR. has a crush on SANDRA BULLOCK – and his wife is NOT happy about it!

The “American Idol” judge has been carrying a torch for the gor­geous “Gravity” actress since the two starred together in “Hope Floats” in 1998, a source says. That was fine while they were living thou­sands of miles apart, but now that the hunky musician is based in Los Angeles while working on the hit FOX show, his wife of nearly 20 years, model Jill Goodacre, is terrified he’ll be tempted to stray.

Although Sandra has done nothing to encourage Harry, “Jill feels threat­ened by Harry’s years-long attraction to Sandy,” said a source.

“After what Sandy went through with her ex-husband cheating on her, she’d never dream of having an affair with a married man. She adores Harry, but as far as Sandy is concerned, they’re friends, nothing more.

“Still, that’s little consolation for Jill, who has been stewing ever since Harry called Sandy and suggested they reconnect while he’s in L.A.”

Harry, who lives in Connecticut with Jill and their three daughters, was quick to offer public sup­port to Sandra, 49, in 2010, when news broke that her then-hubby, Jesse James, had cheated on her. “I think Sandy is an incredible woman,” said Harry, 46. “I send her emails and tell her I love her, and I hope she’s doing well.

“That woman is one of the fiercest, strongest, most dedi­cated people I know. Let’s put it this way, if she was my wife, I would be on my knees thanking God that I had a woman like that.” The source says all that gushing was “like a dagger to Jill’s heart.”

Yet Jill is said to be aware that Sandra, having been married to a cheater, is sensitive to her concerns. “Jill isn’t wor­ried about Sandy,” the source added. “It’s her husband who she’s keeping an eagle eye on.”