POP QUIZ, TWILIGHT FANS. WHY IS AUG. 15, 2010, such a historic date? That’s the day a photographer finally caught Robert Pattinson and Kristen Stewart kissing on a Montreal street corner. At long last, there was verifiable proof that the two actors had fallen for one another as intensely as their characters did onscreen. “They are a couple in love,” says a source who saw them during the Breaking Dawn shoot in Baton Rouge. And they’re finally relaxed enough to let it show-in moderation, of course. “They weren’t slobbering all over each other,” adds the source. “But they sure looked and talked like a couple.” And their stepped-up public displays of affection lasted during the entire shoot. They were often spotted out on the town-listening to music or simply sharing a bottle of red wine while deep in conversation at local hot spots like the Wine Loft and Cadillac Cafe. At one cast dinner, “there was a lot of hand-holding,” says another source. “Everyone was talking around the room, but Kristen and Rob were just talking to one another.” But good luck getting them to divulge any juicy details about their connection. Though the duo has won every MTV Movie Award for Best Kiss that they’ve been nominated for, they have no desire to play kiss-and-tell in real life. Sure, they tantalized fans with that near-smooch at the MTV extravaganza in 2010, but mostly they just frustrate folks by skirting the romance issue and ignoring countless pleas from various media outlets for direct confirmation that they’re an item. Even Oprah Winfrey couldn’t get them to admit on her talk show that they were dating. (Instead, Rob made a joke about Kristen’s being pregnant.) The pair have been playing coy ever since reports surfaced that the shy Brit used to repeatedly propose to Stewart on the set of the first movie. Back then, Pattinson confessed to acting smitten. “I felt like an idiot just following her around saying, ‘You really should read some Zola-and there’s this amazing Truffaut movie,'” he told ENTERTAINMENT WEEKLY. (Her response? “He probably proposes to several girls a day,” she told GQ. “It’s sort of his thing. He thinks it’s cute.”) But if you were paying close attention, you realized Pattinson was truly starting to win over his costar. Their original denials way back when-he’d protest that they were “just friends” and she would ask people to respect her privacy-subtly gave way to flirty banter and body language. He looks at her adoringly during joint interviews, while she likes to rib him about his responses. When Pattinson teased Stewart about “her diva-ish behavior, having the Cooking Channel on at all times” at Comic-Con this year, Stewart shot back, “And you reap the benefits.” (“It’s true,” added RPattz.) Looking back, their love story really began the moment Robert beat out all the other contenders for the Edward role when he and Stewart performed a love scene during an audition. “She would have strangled me if I didn’t pick him,” said Twilight director Catherine Hardwicke in 2008. Pattinson agreed: “There was a certain chemistry,” he said. “She’s the reason I did the movie.” So what’s next for the couple now that their costarring days may be over? Many fans are already praying for a wedding to rival the one that takes place in Breaking Dawn. (“They need to get married in real life,” one fan blogged. “They are meant to be together FOREVER!!!!”) While Stewart seemed to reject the concept of matrimony in a recent German TV interview, she also showed her romantic streak. “I like the thought of two people staying together for the rest of their lives,” she said.