Credit: Twitter

Pretty Little Liars's fourth season is starting the ramp-up to its end. Can you believe the show has been on for so long? A lot has happened in Rosewood over the seasons…  

Every Friday we like to take a look back at an important or memorable scene from seasons past for Flashback Friday. Since it looks like Aria is going to learn that Ezra is a major liar in next week's Season 4, Episode 20 (“Free Fall”), this week we decided to take you back to Season 3, Episode 16 ("Misery Loves Company"), when Spencer realized Toby was part of the "A" team.

While this story had a happy ending (assuming you trust Toby now), at the time, this was absolutely devastating.

The scene begins with Toby, wearing an "A" hoodie, sneaking into Spencer's house, only to find her ready to confront him with the key she found proving he was up to no good.

"Spencer," he says when he realizes he's been caught.

Stoney faced, in total shock, Spencer slaps him. But her anger soon melts into distress as she bursts into tears as soon as her mom comes home.

Later in the episode, she goes to the room he’s staying at and bangs on the door, begging him to explain himself, and sobbing when he refuses to reply. Even though we know it all works out in the end, it's still hard to watch.

Check it out:

What do you think: Will Aria discovering the truth about Ezra be more or less heartbreaking than this? Is it possible to be more heartbreaking than this? Sound off in the comments below.

Catch the next episode of Pretty Little Liars Season 4 on Tuesday, February 18, 2014 at 8 p.m. ET on ABC Family.

Rebecca Martin is an Associate Editor at Wetpaint Entertainment and our resident Game of Thrones, Breaking Bad, and genre TV expert. Follow her on Twitter and Google+!