The 30-year-old reality star worked with the teen singer on a photo shoot last year and was recently asked about his decision to cut off his famous locks into a shorter style.
She said: 'I have seen his new haircut, it's really cute.'
The star was attending her fragrance launch at Macy's in Glendale, CA, and said her new boyfriend Kris Humphries is a fan of the new perfume.
She said: 'He loves my fragrance. I wear it all the time, so he likes my scent.'
Kardashian added that the perfume took a long time to develop as she's so fussy about what she wears.