A source tells E! News that the undercover couple was "all over each other" while attending a rooftop party at the Thompson Hotel. And we're talking full on PDA here, Twi-hards, not just hand-holding. "They were kissing, nuzzling, holding hands and embracing," the source tells us. "He's so into her," says the insider. "The way he looks at her is so passionate." As for K.Stew? She seemed to be loving the attention from Rob. "She was so smiley," says our source.

Kristen ducked out of the official after party early, saying it made her feel claustrophobic. That's when Rob was seen by Hollywoodlife.com, who reported:

Rob hugged his lady love (who had changed from her Elie Saab frock into jeans and a T-shirt) goodbye and whispered, "I'll see you later tonight," in her ear.

This 'are they,' 'aren't they,' back and forth is driving all the Twi-hards nuts! The only thing that should be pointed out here is that Rob has been completely mum about the whole issue. When interviewed, it seems to always be Kristen doing the talking; and she is sticking to her story! Wasn't it Rob that finally confirmed that they are indeed a couple? Maybe it wasn't Kristen that spilled the beans to Oprah, maybe it was Rob?

What do you guys think? Are they together, or is it all wishful thinking?