Taylor Swift — Grinds On Jennifer Lopez During Concert

Taylor Swift + Jennifer Lopez“s ass + songs from 2002 = CONCERT GOLD.

It all went down at Taylor”s concert in L.A. Saturday night. The pretty-straight-laced singer has been inviting a slew of guests to perform with her on tour: Sara Bareilles, Ellie Golding, Tegan and Sara … acts that fit the Taylor mold.

But Saturday she threw that out the window and brought out Jennifer Lopez instead to sing “Jenny From the Block” as a duet … and even tried to rock some fly girl moves.

FYI Taylor fans: fly girls were dancers on “In Living Color“. You probably weren”t born yet.