Two of the world's biggest Instagram celebrities--champion poker player and "Instagram playboy" Dan Bilzerian and fitness model Jen Selter--were out partying this weekend at Selter's birthday party in Las Vegas. 

Bilzerian posted a photo of himself, Selter, and a friend on August 10 on his Instagram, captioned: Happy 21st to @jenselter and her #NeverEndingAss." 

Selter rose to fame after she started sharing her workout and exercise routines on Instagram. Her Instagram page--filled with sexy photos, most of which draw attention her perfect bottom that made millions declare that she has the "world's best butt"--now has over four million followers.

A few days before Selter's party in Las Vegas, Bilzerian was busy flying a chopper with bikini-clad women hanging out in the back seat. It looks like he's doing friend BJ Baldwin (an Off Road racing champ) a big favor, as the photo is captioned, "@bjbaldwin needed me to bail him out in Mexico, so... here I am."

Baldwin seemed grateful, as he posted an Instagram photo of the women captioned, "@danbilzerian found some hot Mexicans too pet my legs after a hard day of racing."

Bilzerian, who now has nearly 4 million Instgram fans and over 800k Twitter followers, also recently gave his two cents on feminism in August 7 on Twitter. "Feminism is bad, I'm glad to see our youth is fighting back," he wrote.

The professional poker player tweeted this statement with a link to a BuzzFeed article about the #WhyWeNeedFrats movement, a new online campaign where guys give their reasons for joining fraternities.

Followers were quick to reply, saying things like "Real men are not afraid of feminism," "you seem far too intelligent for satire like this to go over your head," and "shoulda seen that coming."