It Happened . . . Nicki And Drake Were Caught MAKING OUT . . . Backstage At SATURDAY NIGHT LIVE!!!

Drake and Nicki might not be a FULL BLOWN couple . . . but they are definitely SOMETHING!!!

According to a member of the Saturday Night Live CAST, Nicki and Drake's hot performance got even STEAMIER back stage. The insider told MediaTakeOut.com, "Nicki's boyfriend [Safaree] wasn't there and Drake was all over [Nicki]. Nicki was laughing and pushing him off, but she was also flirting . . . sitting on his lap, and kissing him on the cheek."

But things got STEAMIER. The COMEDIAN/ACTOR told MediaTakeOut.com, "Everyone was drinking [alcohol] . . . and by the time the show was over, they were making out. . . I couldn't believe it."

And shortly after the two LEFT with each other . . . neither showed up to the after party . . . even though they were BOTH scheduled to attend.