LEONARDO DiCAPRIO ’s latest girlfriend is making a huge stink over his hygiene!

The 37-year-old actor and environmental crusader avoids underarm deodorant and daily showers in his bid to help save the planet – but his personal environment has completely turned off his gorgeous galpal, model Erin Heatherton, say sources.

The star desperately needs to clear the air with the 23-year-old beauty, who is also nauseated by his abbreviated bathing schedule, not to men­tion the rancid recyclables that pile up at his house, according to insiders.

“Leo has let his love for the en­vironment take over his whole world, and it’s killing his love life,” a friend told The ENQUIRER.

“He only showers a couple of days a week to conserve water, and he considers deodorant to be ‘unnatural.’ ”

Leo is also an avid recy­cler, but sources say he often misses the pickup days, and the rotting refuse results in a funky-smelling kitchen.

“Erin loves him dearly, but she’s starting to feel like Leo loves the environment more than her!” noted the friend.

Leo went “green” years ago. To save fuel, he insists on taking commercial flights instead of private jets, and he drives hybrid cars.

But the “Titanic” hunk’s obsession is giving Erin that sinking feeling.

And that could be bad news for Leo – previously linked to models Gisele Bund­chen and Bar Refaeli plus gorgeous “Gossip Girl” Blake Lively – because it’s said he’s finally ready to settle down.

“Erin has warned him to clean up his act AND his hygiene,” said the friend. “If not, he may wind up chasing off the woman of his dreams.”