Kim, 33, is set to marry rapper Kanye West in the summer and Kourtney is apparently gearing up to finally marry long-term lover Scott Disick.
However, after seeing Kim marry Kris Humphries in an over-the-top ceremony in 2011, Kourtney, 34, knows what to expect and is worried her own wedding will be overshadowed.
A source close to the famous family said: “Kourtney has already seen Kim have an over-the-top wedding with Kris Humphries and now she’s watching her sister turn her Kanye West date into another big affair.
“She’s getting mad that her own wedding will be overshadowed.”
After being together for seven years and having two children together, son Mason, 4, and Penelope, 1, Kourtney and Scott, 30, are reportedly planning to marry in Mexico, while Kim an Kanye are planning a lavish ceremony in Paris.
“For a really long time Kourtney has felt like she is living in Kim’s shadow but she doesn’t want her wedding to be second to Kim’s THIRD trip down the aisle.
“Everyone knows that Kim is the most popular sister and Kourtney wanted her wedding to be special, so she’s not planning to let Kim steal her spotlight.”
Meanwhile, it was revealed on the most recent episode of Keeping Up With The Kardashian’s that Kim and Kourtney’s sister Khloe felt ‘guilty’ when she filed for divorce from husband Lamar following allegations of his infidelity and drug use.