As much as Severus Snape enjoyed giving his students the impression that he was infallible, he was not. Upon occasion, upon the very rare occasion, he would make a slight miscalculation.

And drinking alcohol after ingesting the potion that he'd so laboriously brewed was a definite miscalculation.

He could have purchased the potion. It had become quite common, after all. But he was a Potions Master; it went against the grain to purchase something that he could make himself. Besides, he thought with a grimace, he wanted to avoid what he imagined would be the knowing leer of the shop clerk as he purchased the Wizarding equivalent of the Muggle drug Viagra.

It wasn't that he needed this particular potion. Oh, no, not at all. But, he thought ruefully, he was 68 years old and occasionally extra... assistance... was helpful. And he'd promised his wife a New Year's Eve to remember. This was, after all, the 25th anniversary of the night they'd become engaged and she was still such a sentimental Gryffindor at heart.

He had surreptitiously consumed the potion at 11:30, knowing that it would take effect in approximately an hour. That would have been plenty of time to see in the New Year before saying their good-byes and Apparating home. However, shortly after Severus drank the potion, Harry Potter had insisted upon making a toast to old friends and had raised his glass to Hermione. Severus had automatically taken a drink of the champagne that had sat untouched beside his plate. The alcohol acted as an amplifier for the potion and the carbonation in the champagne had forced the alcohol into his bloodstream that much faster.

Thus, at 11:55 p.m., he found himself with a painful erection and a wife who was looking forward to ringing in the New Year surrounded by her friends. Severus shifted in his seat, trying in vain to find a more comfortable position and he finally leaned toward his wife.

"Hermione," he whispered, "we should leave now."

His wife gave him a look that he was familiar with so many years of marriage. It was the "are you insane?" look.

"It's almost midnight," she whispered back. "I know you've never cared for Harry and Ron or their wives, but can't you hold out for another five minutes?"

"Actually, I'm not certain that I can," he said dryly. He took her hand in his and placed it in his lap. As her palm rested on him, he bit back a moan. His wife's eyes widened and her face suddenly flushed.

Quietly, he explained to her about the potion.

Hermione's breath caught in her throat. "How long does this particular, um, effect last?"

"Approximately one hour," he said, smirking at her reaction.

"Beginning when?" Her voice was little more than a squeak.

"Ten minutes ago."

Hermione stood so abruptly that her chair fell over with a crash, drawing all eyes to her. "Lovely party," she said breathlessly. "Thanks so much for inviting us but we really must be leaving."

Surprised, both Harry and Ron Weasley stood.

"Why the rush?" Ron asked with a puzzled look. "It's almost midnight."

"Yeah," Harry chimed in, "surely you can wait another minute."

By then, Severus had one hand at the small of Hermione's back and was already steering his wife toward the door.

"Nope, sorry. We really have to run," she threw over her shoulder. "I'll owl you and we can have lunch. Goodnight!"

The clock began striking midnight when Severus and Hermione reached the foyer and they Apparated directly into their bedroom.

Hermione grabbed Severus by his robes and pulled him down onto the bed with her and he brushed a kiss across her lips.

"Happy New Year, my love," he said.

Hermione grinned and slid a hand between them, grasping him firmly. "Happy New Year, indeed."