NBA great MAGIC JOHNSON is terrified his gay son’s party-hearty lifestyle will put him at risk for contracting the AIDS virus, sources say.

The former Los Angeles Lakers star was diagnosed with HIV in 1991 and believes he contracted the virus through unprotected sex. Now Magic, 53, fears his flamboyant 20-year-old son Earvin Johnson III, known as E.J., will booze his way to a similar health crisis if he’s not careful, sources say.

“Magic’s tried to have a con­versation with E.J. about not drinking, at least until he turns 21,” revealed a source. “But E.J. is a headstrong young man.

“NEVERTHELESS, Magic has pointed out to him that drinking leads to poor decision-making, especially when it comes to sex.”

E.J., a student at New York University, came out to his famous dad and mom Cookie years ago. But his sexuality made headlines recently when he was photographed clutching hands with his boyfriend on L.A.’s Sunset Strip.

Afterward, Magic told a reporter: “I love E.J. so much, that’s my main man…I’m behind him a million percent.”

But sources say Magic became deeply concerned about his son’s partying after E.J. posted a message on Twitter last August about getting free drinks at a Big Apple gay bar called TOY. E.J.’s boozing is especially worrisome to Magic, who once filmed a public service ad for Coors beer as part of a campaign against underage drinking!

“Now that he’s ‘out and proud,’ Magic feels that E.J. has a duty to set an example for other young gay men to act responsibly,” said the source. “That means waiting until he’s 21 to go out drinking – and, even then, to watch how much he consumes.

“The last thing he wants is for E.J. to become HIV-positive.”