Robert Pattinson and Kristen Stewart

Summit Entertainment, the producers of the upcoming "Breaking Dawn, Part 2" film, are "freaking out" because they have yet to get Robert Pattinson to commit to personal appearance dates for the film's promo tour.

According to the NY Daily News, the 26-year-old actor is leery of making the promotional appearances with co-star and ex-girlfriend Kristen Stewart, who cheated on him with her "Snow White and the Huntsman" director Rupert Sanders.

“Taylor, Kristen and Rob always fly together,” said an insider, adding that if Pattinson refuses to do the dates with Stewart the studio will “have to spend a lot more money on jets and other expenses” to accommodate the split.

However, Summit execs haven't given up yet.

“Apparently, [Kristen and Rob] have been talking again,” said the source, so the studio “is holding out hope that they'll do the tour dates together.”

“They're prepared for the fact that Rob might not want to, since he hasn't committed to anything yet."