Golf great Tiger Woods and girlfriend Vanessa Trump are taking a swing at a trial marriage as they race toward a formal engagement, according to sources who say pals are warning the wealthy sports star to protect his $1.3 billion fortune with a prenup to avoid being taken to the cleaners.

Sources claim the 49-year-old links legend is “enamored” of the former daughter-in-law of President Donald Trump and sees living together as the next logical step in their relationship, which quietly began in November.

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“Tiger is all in and saying this is a go,” a source says. “He seems certain this has marriage potential. He’s madly in love with Vanessa. Anyone can see it in his eyes.”

“He wanted her to move into his Florida mansion, and she’s essentially living with him now. She was there all the time anyway,” the source continues. “She had drawers and cubbyholes for all her personal items. She cooked meals there. So it was a no-brainer as far as Tiger’s concerned.”

“Word is, Tiger’s instructed his staff to accommodate Vanessa with whatever she needs — no questions. Whatever Vanessa wants, Vanessa gets,” the insider confides.

Tiger and the 47-year-old former model — whose 13-year marriage to the president’s namesake son ended in a cordial divorce in 2018 — happen to send their children to the same prestigious school in Palm Beach.

Tiger is dad to two kids by ex-wife Elin Nordegren, who dumped him in 2010 for his cheating ways, while Vanessa is a mom of five by Donald Trump Jr. — and the new couple’s combined brood has reportedly given their blessing to the romance.

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“Tiger is looking at Vanessa as his next bride. He’s talking about what type of wedding he wants and telling friends he doesn’t see the need for a prenup” the insider says. “They want him to be happy, but to not go into it quite so naively.”

But the source adds, “Tiger is a changed man — and ready to prove it with Vanessa.”