Kourtney Kardashian lost her son Mason at her sister Kim Kardashian West's wedding.

The 'Keeping Up With the Kardashians' star has reminisced on the time she found her nine-year-old son snoozing away under a table just before he was meant to be walking down the aisle with the rings for his 38-year-old auntie and her now-husband Kanye West.

Taking to her Instagram account to wish Kim and Kanye a happy 5th wedding anniversary, Kourtney - who also has daughter Penelope, six, and son Reign, four, with her ex-partner Scott Disick - said: ''My absolute favorite photo from Kanye and Kim's wedding is this one of Mason. We couldn't find him, it was almost time to walk down the aisle and he was the ring bearer. We finally found him asleep underneath a table in the back room in the old Italian fortress where we were all getting ready. My baby is so big now Penelope was just a baby at the wedding and Reign was in my tummy but nobody knew yet. Happy five year anniversary! (sic)''

And Mason wasn't the only one who was nearly late at the wedding, as Kim recently revealed she almost missed Andrea Bocelli's performance because she was delayed leaving Paris.

She wrote on Instagram: ''This was my wedding day almost 5 years ago in Italy. We flew in from Paris and our glam was rushed as we were trying to make it on time! We barely got my veil in as I was being pushed out the door so fast to walk down the aisle because Andrea Bocelli had started singing and I couldn't miss it. I had no idea it was really him until I got to the isle and screamed inside! So many amazing memories. (sic)''

Kim and Kanye, 41, have gone from strength to strength in the years since and now have four children; North, five, Saint, three, Chicago, 16 months, and 14-day-old son Psalm together.

A source said of the couple: ''Kim and Kanye are bursting with happiness over Psalm. He's such an incredibly great baby, and so far, it's been an easy addition to the family...

''Kim and Kanye are both busy with their projects, but have slowed down a bit recently to spend quality time with Psalm ... The kids instantly fell in love with him. North will always be the one in charge, but she loves her little brother.''