Los Angeles, California - Ariana Grande spilled on working with Ben Stiller and Robert De Niro in the comedy, Focker-in-Law on The Tonight Show Starring Jimmy Fallon!

The 33-year-old and her co-stars hilariously crashed the host's opening monologue with a rendition of O Christmas Tree.

Later, Ari gushed over working with Stiller and De Niro and landing the role of Olivia, the fiancée of Henry Focker.

"First of all, I was so honored to be asked. When John Hamburg sent the script, our incredible director and writer, fell in love with it," the Wicked star explained.

Kim Kardashian Kim Kardashian and Kylie Jenner twin in head-turning looks at the LACMA Art + Film Gala!

She continued, "I was just like, 'How have I earned the right to even read this, let alone join this incredible cast and play on set with the most incredible actors and comedians in the world?'"

The No Tears Left To Cry hitmaker announced her hiatus from the spotlight in August, though her rep did clarify that she would still promote the sequel.

Ari defended her decision as "not a reactive or impulsive," adding, "Boundaries need to be set, human beings can need a break sometimes, and also, this can be and will continue to be the greatest experience of my professional and creative life."