"I'm so excited, obviously," Kylie told E! News during a photo shoot for their new clothing collection debuting this month at PacSun stores. "I love having nieces and nephews running around because I'm the youngest out of everyone."
As for their sister's impending motherhood, Kendall added: "It will be good for her."
As for potential baby names for the tiny tyke, both girls admitted they don't have any specific ones in mind.
And while Kylie definitely thinks Kim and Kanye should "retire" the family's penchant for K names, Kendall disagrees.
"I think it would be cute. It's a tradition," Kendall said.
Meanwhile, Kylie laughed off that fake photo that made its way around the Internet recently of what appeared to be her holding hands with Justin Bieber. Turns out, someone had simply Photoshopped Kyle's head onto Selena Gomez's body.
"No, not dating him," she assured us.
Don't miss Kourtney & Kim Take Miami Sundays at 9 p.m. on E!