Timothée Chalamet brought the ladies in his life to a “Marty Supreme” event Monday night … with both his GF Kylie Jenner and his mom Nicole making an appearance.

The actor attended a special screening of his Oscar-nominated film at DGA Theater in L.A. … and did a live interview afterward onstage for LeBron James and Steve Nash‘s podcast “Mind The Game.”

TMZ obtained video of Chalamet and Jenner hanging out backstage … chatting with several people — including fellow Academy Award nominee William H. Macy.

While Nicole isn’t in the video, we do know she didn’t miss her son’s big moment … because she posed for a pic with LeBron — grinning from ear to ear while locking the 6’9″ basketballer in a tight embrace.

It’s been a busy week for Timothée and his mom … they attended the Actor Awards together on Sunday.

While he ended up losing the Outstanding Performance by a Male Actor in a Leading Role trophy to Michael B. Jordan, Nicole won an even bigger prize … Kris Jenner called her “gorgeous” in her Instagram comments!