Kris Jenner and Kourtney Kardashian
07/11/2011 at 01:00 PM EDT
is planning her wedding
, Khloé Kardashian tied the knot
in 2009 – and even mom Kris Jenner became an ordained minister. But there's one Kardashian who doesn't have marriage on her mind.
Older sister Kourtney Kardashian says she isn't rushing toward the altar with boyfriend Scott Disick, with whom she has a son, Mason, 19 months.
"I'm just as much of a family as someone else who has a piece of paper," Kourtney, 32, said on Sunday's episode of Keeping Up with the Kardashians
But with Kourtney thinking of having another baby, both Kim and Jenner were quick to make her consider making a trip down the aisle. "Why is [Kourtney] holding back?" Jenner asks. "Why is she being so stubborn?"
Disick, too, is "on the same page" as Kourtney's mom, who became an ordained minister in the episode to marry a family friend. "I already feel like a lot of times, it's just her and the baby, and then it's me," Disick tells his therapist, explaining that they don't always sleep in the same bedroom because of Mason. "Sometimes I'm jealous."
But Kourtney explains her logic with numbers. She's think he's the one – she's just not convinced he's "100 percent" yet. Disick, who struggled with sobriety
, sought professional help for alcohol abuse earlier this year.
"Until I really know that he's, like, 100 percent, I don't want to put Mason through what we went through with Mom and Dad's divorce," she explained, referring to Jenner's first marriage with attorney Robert Kardashian. "I know how hard that could be on kids."
Last month, Kourtney said sister Kim's engagement, which has yet to play out on TV
, took pressure off her
to take the next step in her relationship. "Kim getting engaged definitely bought me some time," she said, "so I don't have to go out and get married right now."