Kendrick plays mommy vlogger Stephanie Smothers who is trying to uncover the truth of the disappearance of Lively's character, Emily Nelson. Lively said she enjoyed the role thanks to filmmaker Paul Feig, who "creates such fun, delicious women."
The two women share an onscreen kiss, which Lively described to Roberts as the "mintiest" kiss ever.
"It's always confusing when you share a kiss with a costar," Lively said. "Nobody wants to be the story of like, dragon mouth."
Lively also talked about her character encouraging women to stop apologizing.
"I find that we apologize for asking what we want a lot." She said.
Lively also discussed her sixth wedding anniversary with fellow actor Ryan Reynolds and parenting their two daughters.
Watch the full interview below.