The flashback will be when Sophia went to her first concert. Which is also the first time she ever drank. Which caused her to strip naked and run on stage. Yes, Sophia was a streaker!
Flashforward to today. Sam just happens to be a musician. And even more importantly, Sam happens to have a bottle of the same type of liquor that Sophia drank way back when.
Then, as Sam plays Sophia a song on his guitar. Sophia is slamming back some shots. Reminiscing on the good ol' days where she wasn't a nun. And as history repeats itself, Sophia gets naked and streaks around his room!
And, just like back then, security will come and escort her out. And by security, I mean Sam's mom. And by escort her out, I mean throw her out a window. Only Amber is allowed to seduce her friends son!