Pattinson, 26, sat next to Stewart, 22, during a chat for MTV, with the actress even talking about their love scenes in Breaking Dawn: Part 2.
"I feel like every scene in this movie culminates with a kiss," she says in an interview streamed live on PEOPLE.com. "We always really, really prepare. [We] execute our plan well."
In a separate sit-down with ET's Nancy O'Dell the pair, joined again by Taylor Lautner, were all business, fielding only questions about making another Twilight movie.
"It felt a lot more free in the first one," Pattinson said, comparing the final film in the saga to the original. "It felt quite dangerous. The bigger something gets, it gets pretty heavy. You're part of a machine at that point. You know your face is on the front of it, but you have a lot less control."
The night before, the recently reconnected couple made their way to the Hollywood Forever Cemetery for a Maroon 5-hosted Halloween celebration, where guests sipped on drinks in the Patron XO café.
Adds an additional insider, "They shared drinks with friends at the party and were in a good mood. Rob was all over Kristen, while she seemed a bit more reserved."
At one point, the pair was checking out Johnny Ramone's grave.
"They were sitting on the ground next to it," the first source says. "They were chatting and sipping on cocktails."
Pattinson was then spotted returning to Stewart's home with her just after midnight.
With reporting by PERNILLA CEDENHEIM