Boston- They know A-Rod prefers blonds – maybe they heard A-Rod likes to be teased, too.

Hundreds of Red Sox fans donned yellow-haired masks last night, taunting Yankees star Alex Rodriguez about his liaison with a buxom blond stripper.

The public ridicule came hours after the Yankees $252 million man made nice with his wife, Cynthia – spending $6,000 on diamond necklaces for her.

“This is what I like,” she told him in the Persona gift shop in the lobby of the Ritz-Carlton hotel in Boston.

“Go ahead, get them,” the stripper-loving slugger urged her, according to a witness.

As the couple browsed, the New York newspapers, with headlines about the ballplayer’s ties to a Scores dancer, were in full view.

They giggled as they looked at the front page of the Daily News, which bore a photo of them, and Cynthia cracked, “At least it’s a cute picture of us.”

Later, after A-Rod had left the hotel for Fenway Park, his wife came to the lobby in workout clothes to pick up the two necklaces.

She seemed happy about the gift, even though it was hardly lavish by the standards of mega-rich professional athletes.

After L.A. Lakers star Kobe Bryant admitted he was unfaithful, he shelled out $4 million on a diamond ring for his wife, Vanessa.

Rodriguez has not publicly explained his relationship with the stripper, Joslyn Morse, since photos of the two of them visiting a Toronto all-nude club surfaced this week.

“It’s personal,” he said yesterday as he arrived for the game at Fenway.

Morse, 30, has reportedly been spotted with Rodriguez at hot spots around the country.

Just two weeks ago, on May 14, the two were seen at Scores in Las Vegas, where she had worked for about a year until October, sources said.

“She wasn’t working. They were in the audience,” one source said.

Morse is originally from Cedar Rapids, Iowa, where her father is a postal worker and her mother is the religious education director at a Catholic school.

She racked up a string of speeding citations and one petty theft arrest as a teenager and then left town, moving from Georgia to Texas to Vegas, according to public records.

In May 2000, she showed up to a casting call for Playboy in Sin City, hoping to be recruited as a Playmate or a Bunny.

She didn’t make the cut, but the test photo, a Polaroid, was selected for Casting Calls magazine, a Playboy spokeswoman said.

It’s unclear how long she has known Rodriguez, who is a fixture at flesh emporiums here and in other cities – even though he has a wife and 2-year-old daughter.

A year ago, he visited Iniquity, a swinger’s club in Dallas, with a pretty brunette he introduced as his publicist and another couple, a witness said.

They sat in the mezzanine overlooking the main floor and surveyed the action but didn’t participate, according to someone there that night.

“He was very nice, treated everyone with respect,” the person said.

Rodriguez’s extracurricular activities didn’t land him in hot water until a paparazzo snapped him and Morse outside the Brass Rail strip club in Toronto on Sunday and then tailed them to the Four Seasons, where they were seen getting onto an elevator.

Before last night’s Red Sox game, outfielder Johnny Damon acknowledged his teammate’s indiscretions could affect the Bombers’ performance.

“What he does in his personal life we can’t judge – but it can be a distraction,” he said. “Hopefully, he comes out and plays to full capacity.”