Could it be over for Twilight's hottest couple?

On July 17, Kristen Stewart, 22, was photographed getting rather cozy with her Snow White and the Huntsman director, Rupert Sanders, 41.

This may come as a shock to Stewart’s boyfriend, Twilight costar, Robert Pattinson, 26, who were all laughs just days ago at Comi-Con.

A source tells PEOPLE that the pictures are a bit misleading and Stewart just had a minor lapse in judgment.

"She wasn't having an affair with Rupert. It was just a fleeting moment that shouldn't have happened.  She never meant to hurt anyone. She's a good person who just made a bad choice."  The source continues to explain, "Kristen is absolutely devastated, it was a mistake and a complete lapse in judgment."

The young Twilight couple, who met on the set of the first movie, has just recently become more public with their relationship.

Sanders is married to British Vogue model Liberty Ross, 33 and they have two children ages 5 and 7.

Reps for Stewart and Sanders have yet to comment.

UPDATE:  Kristen Stewart has issued a public apology after photos surfaced of her getting romantic with her Snow White and the Huntsman director, Rupert Sanders.

In a statement released Wednesday, the Twilight star had the following to say:

"I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected. This momentary indiscretion has jeopardized the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I'm so sorry.”

Robert Pattinson and Kristen Stewart first met on the set of Twilight and feel in love both on and off the screen, they’ve been together for 3 years.

Meanwhile, Rupert Sanders has released an apology exclusive to PEOPLE:

"I am utterly distraught about the pain I have caused my family.  My beautiful wife and heavenly children are all I have in this world. I love them with all my heart. I am praying that we can get through this together."