CAMERON Diaz wants her SexyBack.

But she’s not going to win back Justin Timberlake if she follows him around and accosts the women he flirts with, as Page Six reported Tuesday. And she’s not going to win any points by dressing like a giant cake-topper at the Golden Globes, either.

“Jealously is so unattractive and gives the power to the other woman, and it makes Cameron look like a basket case,” said Nancy Wesson, a relationship counselor at KeepYourMarriage.com.

Outbursts will only reinforce his decision to retreat and view you as a hysterical woman.

“Cameron has to recognize that, at this point, the ball is in his ballpark,” says Michelle Weiner-Davis, author and founder of DivorceBusting.com. “Relationships are like seesaws. If she is going to do all the chasing and caring, that leaves room for him to do none of it. What attracted him to her was her independence and strength, and now she is showing another side which is not so attractive.”

“The No. 1 thing that drives men crazy and scares them off when you’re dating is neediness and insecurity,” writes relationship author Christian Carter in his book, “Catch Him & Keep Him.”

Carter advises staying away from discussions that might include complaining about the current state of the relationship, talking about the things he does wrong with you, showing your frustrations about what you feel is missing, becoming upset that he doesn’t feel how you’d like him to feel, and bringing up past issues, arguments or disappointments.

Wesson says it would be much more powerful for Diaz not to be flirting with other men – because that is immediately seen as a ploy – but to be calm and centered and look as if she was enjoying her life.

If Cameron runs into Justin at another event, she also has to find a brief moment to calmly apologize for her behavior and tell him that she only wishes the best for him, advises Wesson. “Neutralize what’s happened so he can have a more pleasant association when he sees her the next time.”

Weiner-Davis also believes in remaining as friendly and as positive as possible, even when infidelity is involved.

“When we give our partners the benefit of the doubt, we treat them lovingly and respectfully. If, on the other hand, we assume the worst about our partner’s actions or intentions, we behave in self-defeating ways,” Wiener-Davis writes. “Approaching one’s mate with boxing gloves is not likely to bring out the best in him or her.”

For Diaz, and anyone who hopes that a relationship isn’t over, our panel of experts advises:

* Don’t panic. Just because a breakup is happening doesn’t mean it’s the final sentence. The marriages that last are the ones in which partners do not see conflict as nailing the marital coffin shut.

* Pull back. Give them time to miss you. Don’t chase, e-mail, phone or send flowers. Instead, become the desirable prey. Let him think he’s in the driver’s seat.

* Act confident. It’s a turn-on. Remember what it is about yourself that attracted your partner in the first place. Act confident and strong in their presence, and make yourself feel you are going to go on with life no matter what happens.

* No public brawls. Ending up on Page Six or in the local paper’s police report won’t endear you to each other or your neighbors.

* Work on yourself. Do yoga and exercise and find poise. The work is not how to change him or get other women to leave him alone. Instead, the work should be on you.

* The grass isn’t greener. All relationships need work, and trading in for a new partner merely changes the problems. Know which ones are deal breakers. Identify relationship strengths and build on them.