It was just mistletoe, you didn't really have to kiss under it did you? The correct answer to this question is yes you did. Hermione found this out the hard way when her and Harry were coming back from the library.
"I just don't understand" Hermione said when she found she couldn't move. Harry had blushed a deep red.
"We have to kiss Hermione"
"Oh!" she said, also turning a deep red. Hermione leaned forward a bit and pecked harry quickly on the lips. Hermione found out later that Dumbledore had charmed a bit of mistletoe so that you did in fact have to kiss. Hermione avoided walking with people from then on. Today she was late, which she found odd, as she was never late. Not late to class, late to lunch where she promised she would help Harry and Ron with their homework. She was turning the corner, shoving her book into her oversized bag when she ran into someone.
"Oh Professor Lupin I'm so sorry!"
"Quite all right Ms. Granger" Lupin said, dusting himself off.
"I'll just be going" Hermione said, turning to walk away but finding she could not move. Lupin sighed very loudly.
"This isn't appropriate Dumbledore" Lupin shouted. Hermione's face turned red upon realizing she had to kiss one of her professors. Lupin rubbed his face and sighed again.
"There's no way out of it" Hermione nodded. Lupin frowned but leaned down to kiss Hermione. Hermione found that Lupin was very pleasant to kiss and Hermione found herself touching her fingers to her lips long after he had left.