Michael Phelps and his (sorta) new bride Nicole Johnson hit Sin City together this weekend for the first time as man and wife (as far as we know) ... and partied their faces off with Diplo!
Interesting note ... neither Michael nor Nicole were pictured with an alcoholic beverage in their hands. As you probably know, Phelps has battled issued with booze over the years but has said he hasn't sworn it off completely.