TMZ obtained the photo taken backstage during an Aerosmith concert in Bristow, Virginia -- and the story behind it is pretty wild.
Tareq Salahi is telling friends he and Michaele (aka "groupie slut") went to the show together without backstage passes -- oh, the horror --but then Michaele mysteriously disappeared for more than an hour.
We're told ... when Yoko Michaele returned she produced the photo with Steven AND an all-access backstage pass for ALL Aerosmith concerts!
We're told Michaele's explanation for the pic, at the time, was ... she and Steven were just seeing who had a flatter stomach. Steven's rep had no comment.