"The girl can't help it. @katyperry," Kendrick, 28, captioned the picture.
The new besties were attending the celeb-filled event hosted by Reese Witherspoon and her hubby Jim Toth, which benefited cancer research.
But this wasn't their first cleavage-filled encounter. At the Jan. 26 Grammy awards, Kendrick wore a cleavage-baring cream-colored Azzaro gown to present and Perry performed her latest single "Dark Horse" for the celeb-filled crowd.
And in a January appearance on Conan, Kendrick told host Conan O'Brien about the Grammys, recalling, "Katy Perry finger-banged my cleavage. I was kind of asking for it. If nobody had done it, I would've been a little sad."