"I was like, 'Do I use tongue?' " she laughed during a recent interview with MTV News. " 'Do I not use tongue? Do I cover my teeth? What do I do? Do I go first? Oh my god!' "

With all these questions swirling in her head, she ended up nearly attacking Grint, who plays Ron Weasley. "I ended up pouncing on Rupert," Watson confessed. "I was so desperate to get it over. After the first take he was like, 'Whoa, there! Where did that come from?' I was like, 'Sorry!' "

"It took me by surprise," Grint admitted.

"Kissing [on camera] is always quite embarrassing, because you've got a whole crew of people watching you and it just feels really self-conscious and you don't really know what to do with yourself," he said.

Add in the fact that Watson and Grint have known each other since their pre-teen years, and the kissing scene reached new levels of weirdness. But at least it was a shared weirdness. "The only good side to it was the fact that we were both in the same boat," said Watson. "We were both just like, 'Oh my god, I can't believe we have to do this. This is so awkward. Really awkward.' So I could take comfort in the fact that Rupert felt the same way. We were both giggling. We were like 12-year-olds. We were like giggling children where you just couldn't keep it together."

Yet even more difficult than the actual kiss was the moment after director David Yates yelled "Cut!" "The hardest part was having done the kiss and having to put it away and having a moment of looking at each other," Grint said.

And did Watson think she did well for her first time? "I have no idea if I did it right!" she laughed.