How cute are these two?! Adam Sandler and Drew Barrymore sang a song about their love on The Tonight Show Starring Jimmy Fallon on Wednesday, Feb. 26. Having costarred in three romantic comedies together in their career -- 1998's The Wedding Singer, 2004's 50 First Dates and the upcoming Blended -- the good friends vowed to always love each other through song.

"Every 10 years I promise to love you," Barrymore, 39, sang. "I'll always be true, even as we get older," Sandler, 47, sang back.

The sweet, emotional duet also had its moments of humor. Sandler joked: "I will still love you when your boobs touch the floor." Barrymore, who is pregnant with her second child, quipped: "So, right now?"

Sandler ended the song by singing lyrics from his famous track in the Wedding Singer. "Oh, I could be the man who grows old with you," he sang. "I want to grow old with Drew-y."

Watch Sandler and Barrymore's adorable duet in the video above.