Cheating is as much a part of Odell Beckham Jr.’s game as highlight-reel catches and incredible athleticism.

So said a frustrated Saints defense Sunday after Beckham was one of the standouts in a 16-13 Giants victory at MetLife Stadium that dropped New Orleans to 0-2 by a total of four points.

Veteran safety Sterling Moore pulled no punches in the Saints locker room, saying the Giants’ star wide receiver regularly commits offensive pass interference that is ignored by the officials and was allowed to continue unabated again Sunday.

What set Moore off was the highly questionable, 23-yard interference penalty he got in the first quarter while defending Beckham on a third-and-8 play near midfield that gave the Giants the ball at the New Orleans 24.

Moore’s disgust only grew on the next play, when he said Beckham was allowed to get overly physical en route to a 13-yard completion.

“I didn’t like it, man,” said Moore, a journeyman in his first season with the Saints. “It was one of those things where [Beckham] is trying to pull himself through. He does that a lot, and he kind of gets away with it at times. It’s something I mentioned to the refs. It is what it is.”

Moore redeemed himself temporarily, ending that drive by breaking up Eli Manning’s pass to Beckham in the back of the end zone when Giants coach Ben McAdoo gambled by going for it on fourth-and-2 from the Saints’ 3.

But Beckham and the Giants got the last laugh, with Big Blue pulling out the victory on a Josh Brown field goal at the gun after Beckham tied teammate Sterling Shepard with a game-high eight catches for 86 yards.

Beckham is no stranger to Moore, who faced the Giants All-Pro last year with the Buccaneers and during Beckham’s 2014 rookie season as a member of the NFC East-rival Cowboys.

Moore told The Post pushing and pulling is “Beckham’s staple on those deep balls.”

The Saints knew that coming in, Moore added, and lobbied referee Gene Steratore’s crew before the game about keeping Beckham in check. But their lobbying proved fruitless.

“They obviously brushed it off,” Moore said. “It’s something he gets away with pretty regularly. I guess it’s something you’ve got to live with.”

Added fellow safety Kenny Vaccaro: “You can sit here and complain if you want, but that’s just the way it is.”

It was especially frustrating for the Saints because their beleaguered defense played one of its best games in years, holding Beckham and the Giants without an offensive touchdown a week after getting torched for 35 points against the Raiders.

Moore said days like Sunday are why defensive backs around the league will start to resign themselves to Beckham — a Louisiana native son who starred at LSU — being given the hands-off star treatment.

“It didn’t surprise me that he was doing it,” Moore told The Post. “But it surprised me that they were letting him do it and were letting us go out there and play. I guess that’s how it’s going to be.”