(Olivia Harris/Reuters)

A couple of weeks ago during the London premiere of “The Amazing Spider-Man 2,” star Andrew Garfield was quite rude to a red carpet reporter who deigned to call Emma Stone his girlfriend.

To regular tabloid readers — or even those who take a cursory glance at People magazine in the grocery store — that sounds ridiculous, because Stone is his girlfriend. It’s long-established that the two met while filming “The Amazing Spider-Man” in 2010, and have been photographed together (including the inevitable making-out-on-street-corner shots) for years. If it’s all a publicity stunt, it’s a pretty incredible one.

Still, Garfield wasn’t very nice. “Who’s my girlfriend?” he snapped. “You’re making an assumption about my personal life, and my personal life is not public property.” The reporter pointed out the facts: “You’re in a massive film with her,” she said. Garfield wasn’t having it.

Was there fallout over this unpleasant little exchange? Nope, none whatsoever. People and the Internet are obsessed with the couple, and that’s because Garfield and Stone have smartly managed to craft the perfect Hollywood relationship. It’s much harder than it seems.

Really, it comes down to being adorable and down-to-earth enough that demanding your privacy as you make your living from people liking your relationship (enough to maybe, say, buy tickets to “The Amazing Spider-Man 2”) becomes endearing rather than what it actually is — incredibly hypocritical.

Garfield and Stone make that look easy, as the Internet is chock-full of stories dissecting every sweet thing they have said about each other, or lists that chronicle “21 Reasons Why Andrew Garfield And Emma Stone Were The Cutest Couple Of 2013.” And yet, they’ve never even said they’re a couple.

The most important rule: Never directly confirm you’re in a relationship, just concoct an air of mystery that keeps fans intensely curious. As a result, the blogosphere is sent into a frenzy over something like Stone’s “Good Morning America” interview earlier this week, where she gushed about working with Garfield on set. “It’s a dream to work with him,” she said. “He’s obviously one of the greatest actors I think we have alive today and he’s also just a remarkable human being. I love him very much.”

She said “LOVE”? Sure enough, the blogs exploded, making it sound like she confessed a dirty secret. “Emma Stone Admits She Loves Andrew Garfield on ‘GMA’!” exclaimed Just Jared. “Emma Stone’s Rare Andrew Garfield Admission: ‘I Love Him Very Much,'” reported E! Online.

Another key factor: When asked about the other person, simply say very nice things that sound romantic but aren’t obviously so. They are great at this. (“He’s an incredibly important person to me,” Stone said in her Vogue cover profile. ““I thank my lucky stars that we’ve been able to be on this ride together,” Garfield said in the story.)

Then, to top it off, when promoting a project together, get physically close, but not too much. People will see the guy putting his hand on the lady’s back to help her down the steps, and declare him a modern-day Romeo. Or, simply just look at each other: The blogs will declare that a sweet “stolen glance.”

Seriously, celebrities in Hollywood need to be taking notes about how to be totally evasive and yet completely charming. Even Ellen DeGeneres seemed delighted when the couple stopped by her show last month with “Spider-Man 2” co-star Jamie Foxx. Both refused to spill a word as she teased them about their kissing scenes and the sleeping arrangements during promotional tours across the world. (“Do any of the co-stars have to share a hotel room or anything like that?”)

“Just drop it,” Garfield pleaded while Stone giggled and Foxx made all kinds of innuendos. Still no answer from either of them — and fans are still left wondering, and most importantly, caring deeply about the answer.