Spending quality time with her little man, Kourtney Kardashian and Mason were spotted out in New York City on Friday (October 21).

The “Kourtney and Kim Kardashian Take New York” hottie looked trendy as usual in high boots, a dress and fur vest as she and her son, along with Kim visited the Museum of Natural History.

Kourt is helping her sister, Kim, celebrate her 31 birthday today!

Giving her newlywed sis a shoutout via Twitter, Kourtney wrote, “Happy birthday to my favorite sister of the day @KimKardashian! Let’s party like it’s 1980!”

kourt-mason-102111-1.jpg  Kourtney2BKardashian2BKim2BKourtney2BTake2BMason2BSNEu8Ou3fMtl.jpg  kourt-mason-102111-3.jpg  kourt-mason-102111-4.jpg

Candids > 2011 > Museum of Natural History in NYC – October 21, 2011