Orville Peck says he and a Las Vegas Raiders player did some spit-swapping ... singing in his new song that he made out with an NFL star.

The country singer dropped the line in his new track, "Ring the Bell," which came out Friday as part of his "Mule" album.

Orville sings, "I love the Lakers, the Mets and the Longhorns, made out with a guy on the Raiders."

No double entendre here, BTW ... Orville confirmed in an interview with Variety that he did in fact tackle a Raider's lips -- though he didn't say if the two went all the way to the endzone or just stopped with the completed pass here.

Orville does note he got permission to mention the steamy session from the player -- and he even thinks he could've got the guy to sign off on revealing his name ... but he's decided not to say who it is.

He says someone just needs to use common sense to figure out the NFL player's identity ... your turn, internet sleuths.

The Raiders are off to a 1-0 start this season ... and we'll have to wait and see if the kissing and kinda telling helps them run it back on Sunday against the Los Angeles Chargers.