Tyga Still High On High School

10/17/2015 11:57 AM PDT

Tyga is re-living the glory days when Kylie was by his side as she studied for her high school exams ... like 3 months ago. 

Tyga and his 18-year-old GF were in downtown L.A. Friday night shooting a music video.  The theme is becoming predictable, right?

Next Project:  "High School Musical 4" ???