Jen Selter, the fitness model who became a star on Instagram because of all the work she's put into developing her personal brand—which, in this case, is a euphemism for "butt"— celebrated her 21st birthday in Vegas over the weekend. Also there was Dan Bilzerian, another Instagram star known mainly for his millions of dollars and the time he threw a porn star off the roof of his mansion and missed the pool.

Her full, firm fanny has made her an Instagram sensation, with nearly two million followers to her name.