Kendall Jenner -- I’m 18 ... So Here are My Nipples

After only 16 days since her 18th birthday … Kendall Jenner decided to give the world a glimpse of her nipples … leaving everyone wondering ... what took so long?

Now here's the question ... does it all end with nipples, or will Kendall walk the path forged by her older sister, with the helping **** of Ray J?

And while we're at it ... we gotta ask ...