Kourtney Kardashian only takes photographs of her baby.

The reality TV star admits she used to be obsessed with taking snaps of herself at photoshoots but now she is only interested in images of her five-month-old son Mason - who she has with her boyfriend Scott Disick.

She said: "Motherhood has most definitely changed me and my life. It's so crazy how drastic even the small details change - in such an amazing way. Even silly things, like the fact that all of my pictures on my cell phone used to be of me at photo shoots - conceited, I know - but now every single picture on my phone is of Mason."

The 31-year-old beauty and her sister Khloe Kardashian love playing with Mason, but are shocked by how quickly the tot is growing up and developing his own character.

Kourtney explained in her blog on People.com: "My son changes so much every day. Yesterday, he started getting ticklish under his arms and laughing hysterically! It's beyond cute. While Khloe and I were playing with Mason last night, he got up on all fours and was moving all around desperately trying to grab a toy. When he finally scooted himself over to the toy, he stuck it straight in his mouth and was so proud of himself!"