Chris Brown stunned some Harlem pick-up basketball players and their fans when he spontaneously appeared Tuesday evening to play hoops at West 136th Street and Amsterdam Avenue. Spies saw the “Don’t Wake Me Up” singer on the court “for a couple of hours playing with the neighborhood kids,” reports The Post’s Pedro Oliveira Jr. A spy at the outdoor court at the PS 192 Jacob H. Schiff school added, “The place was packed, and there were tons of kids screaming and freaking out.” Pictures posted to Twitter show Brown playing ball in a black V-neck shirt and then addressing some squealing young fans off the court, too. One local said Brown has hit the same court in summers past, and that he used to play there when he moved to New York from Virginia to launch his singing career. While Brown played ball, his ex Rihanna was rocking Brooklyn’s Barclays Center. Brown was later seen at the Dream Downtown, where a source said he’s taken over a top-floor suite. Also at the hotel Tuesday night, Lauren Conrad was hosting a bash for Malibu Island Spiced rum/liqueur with guests including Annabelle Dexter-Jones, Hannah Bronfman and Harley Viera-Newton. Brown had been out partying till the wee hours Tuesday morning when he hit nightclub Griffin with a posse of 20 after the Met Ball.