Lukas Haas and Anderson .Paak are in the Christmas spirit … because Lukas got on the mic at Anderson’s karaoke bar and belted out his new holiday song … and we have it all on video.

Check out this video, obtained by TMZ, from inside Anderson’s music bar in West Hollywood, Andy’s, where Lukas showed up on Christmas eve for a live performance of his new single, “Christmas Cheers.”

The song was originally written for Lukas’ character on the HBO hit “Righteous Gemstones” … and as you can tell, it’s not your traditional Christmas story.

Anderson’s karaoke spot was having an ugly Christmas sweater night too … and he and Lukas played along.

When Anderson was talking to the crowd, he mentioned he was single … which is pretty interesting, considering he was getting close with Mariah Carey over the past year.

FYI … Tuesday is the exclusive Casablanca karaoke party at Andy’s where different VIP’s come and pop-up on stage.

Jordyn Woods got one lucky thing for Christmas this year … a ring — ’cause she is now engaged to NBA star Karl Towns!!!

The couple announced the news in a joint post on Instagram on Christmas day … captioning the emotional carousel of photos with a simple pun — “Marry Christmas.”

Jordyn — dressed in all white — looking as happy as ever with her new fiancé as they stand atop a gorgeous, scenic view at the “Overstory” cocktail bar in New York City.

Travis Kelce and his brother Jason are taking holiday fashion to a whole new level — rockin’ matching Christmas sweaters that each feature a gigantic tree as a not-so-subtle nod to their respective … ahem … “packages.”

For context … in Taylor Swift‘s hit song “Wood,” she sings all about her NFL fiancé’s nether regions … referencing Travis’ manhood as a redwood tree and dubbing it “the gift that keeps giving” … so this surely is quite the package deal.

This isn’t the first time the bros addressed the elephants in the room … Jason Kelce was actually the one who got the footballer to open up on “Wood” during an episode of “New Heights” — and while Travis said he liked it, he was quite shy when pressed to give further comment.

Jason went on to describe which forest friend he’d compare his genitalia to, saying … “It’d be like Japanese Maple,” before adding, “Sometimes can see” — hence the crimson-themed design on his sweater this Christmas.