Thinking of Rob   It's all about Robert Pattinson

“Water for Elephants” co-stars Reese Witherspoon and Robert Pattinson had a busy day on Sunday.

The gorgeous pair spent most of the day conducting press interviews for their stunning new period romance, then were headed to Las Vegas immediately after to present an award at the 46th Academy of Country Music Awards.

However, the beautiful blonde said she and R-Pattz had plans to scrap the quick flight in exchange for a rough ‘n’ tumble road trip.

“We’re actually going to drive,” Reese jokingly told Access Hollywood’s Shaun Robinson at the “Water for Elephants” junket in Santa Monica, Calif., on Sunday, of her and Robert’s impending jaunt to Sin City for the awards. “I’ve got a six-pack and he’s bringing the cigarettes. We’re going to rage like, with an iPod. I’m going to blast the country music – he’s super-duper into it.”

“Damn it — we said it!” Robert added, playing along.

Although the Oscar winning actress married her fiancé, Jim Toth, just one week ago, she’s had to postpone her honeymoon for the time being due to her busy work schedule – but Robert revealed Reese doesn’t mind.

“This is a honeymoon,” Robert answered for Reese, laughing.

“This is a honeymoon! Come on — in here with all of you?” Reese added, laughing. “I will be on my honeymoon soon, and none of you are invited.

“Rob wants to go with me [on the honeymoon] — he’s hinted all day,” Reese told Shaun. “And I have to say, ‘No, you can’t come…’ He’s needed on the set.”

Shaun also confronted Reese with a little known onscreen connection between her and her “Twilight” hunk co-star – the two actually worked together, as mother and son, on Reese’s 2004 drama, “Vanity Fair,” but Robert was left on the cutting room floor.

“Go ahead – tell her,” Reese grimaced.

“Reese played my grandmother,” Robert deadpanned.

“It was bad enough – I played his mother in a movie,” Reese laughed.

“I got cut out of it and she looked like a 15-year-old at the time,” Robert told Shaun. “I didn’t understand what was going on at the time while we were shooting it, and then I was invited to the premiere and I was cut out of it.”