Kristen Stewart might be replaced by Ashley Greene to walk on the red carpet with Robert Pattinson for "Breaking Dawn Part 2" promotions.

It was already announced that Stewart and Pattinson will walk down the red carpet together after Stewart's shocking cheating scandal. But Summit Entertainment has a back up plan.

The New York Post reported, ""The studio's holding out to see if they get back together. But I don't think anyone is banking on that happening," said an insider. "At this point, the press strategy would have been mapped out. It's usually very organized, but at this time it's undecided."

If that doesn't work out, the executives already have a back up plan.

Sources said Stewart and Pattinson could attend premieres separately if they don't reunite. And that Greene (who plays Alice) could step into a more prominent role at promo appearances should fans' dislike toward Stewart continue.

Twi-hards are dying to see their Bella and Edward together once more, not Edward and Alice, and not just in the movies.

Greene acted as the main lady with Pattinson for the French and Belgian premiere of "Breaking Dark Part 1" last October when Stewart was busy filming "Snow White and the Huntsman."

Rumors were floating around that Greene and Pattinson were once romantically involved. CrazyDaysandNights reported that Pattinson, 26, engaged in trysts with Greene while he was dating Stewart, 22.

In a 2010 interview with Daily Mail, Greene was happy to praise Pattinson.

"Robert Pattinson, who plays my adoptive brother in the Twilight films, has been one of my biggest inspirations," Greene said. "As a person, he's not like anyone I've ever met in Hollywood, and as an actor he's a complete natural. He has no ego. Everyone loves him, but he's una­ffected by that and never seems fazed by the attention that comes his way. He's not changed a bit since I worked with him on the first Twilight movie. He's a great night out if you tag along with him to a pub or bar. He's not the nightclubbing, get-up-and-dance kind of guy, but during shooting we'll join him back at his hotel, where he'll get out his guitar and we'll have a loud singalong.

It was recently revealed that Stewart is having a really tough time after she publicy apologized for cheating on her boyfriend of three years with "Snow White and the Huntsman" director Rupert Sanders.

"She isn't sleeping and she stays up all night crying," reports RadarOnline reported. Sources said she is "close to a total meltdown."

It was also revealed that Pattinson might be moving back to London, where his family and friends are.

"Robert is thinking long and hard about returning to London," a source close to the star revealed to RadarOnline.

"He's selling his home in Los Angeles, not only because it holds bad memories, but because he wants a fresh start.

"He never fell in love with Los Angeles and has always longed for home. When Kristen was shooting Snow White and the Huntsman in London, he made his excuses to visit her as much as he could - he missed it so much."

What do you think? Would you rather see Robert Pattinson walk down the red carpet with Ashley Greene? Share your thoughts below!