Ben Simmons wouldn't say ... but his smirk told us everything we needed to know.

TMZ Sports got Ben hitting Delilah and Warwick with 76ers bro Robert Covington after they took out Lonzo's Lakers at Staples -- why not celebrate, right?!

Simmons straight up dominated their matchup ... so when we asked about his dunk that sent 'Zo to the shadow realm, Ben reacted pretty much how you'd expect.

B.S. seems to love the club scene -- and so far, it hasn't impacted his play. He was out early Wednesday morning and still killed it later that day.

FYI, we bumped into a couple of the 76ers assistants on gameday ... and they didn't seem to mind.