Adam Sandler just waxed poetically about Taylor Swift -- letting the world know he's a MASSIVE Swiftie who's rooting like hell for her relationship with Travis Kelce to work out.

The actor and comedian couldn't stop praising the "Cruel Summer" singer while on with the Kelce bros on this week's episode of "New Heights" -- raving about the popstar for nearly three minutes.

Sandler -- who will be reprising his role as Happy Gilmore soon -- said Swift means so much to him and his family ... he actually gets butterflies when he's around her.

"I do get nervous around Taylor Swift," he admitted, "because I don't want to f***ing blow it for my kids and say something stupid."

"So, I'm just like, 'S*** she means so much to my f***ing house I better say the right thing!'"

Sandler explained his family listens to her music regularly -- and never skips a song on her albums. In fact, he stated he actually brought his kids to the premiere of Swift's the "Eras" tour film, which Travis said she was "very grateful" for.

Sandler then dove into how much he loves Travis' relationship with Tay Tay.

"When you guys first started dating, my god, was my family like, 'Yes! Look how good they are together, he's a gentleman! And she's having so much fun with him,'" he said. "Like any time Taylor is laughing with you, my whole f***ing family is like high-fiving."

Goes without saying -- if wedding bells are in the future ... Sandler wants to be there -- whether he's singing at it or not.