James sniggered, until he heard Madame Pomfrey coming to check on their progress... With no time to waste, he hissed to Lily, "Quick! Switch back!" Lily quickly ran to Snape's feet, and James went up to Snape's thin, white arm and began applying anti-boil cream (though not quite as liberally as before).
"How is everything here?" the nurse asked. She noted that Snape's robe had yet to come off. Instead, the black material had been pushed up to his knees and shoulders.
"Everything's fine here, Madame Pomfrey," Lily said. "It's just great." She smiled, hoping to convince the nurse to leave more quickly. However, Lily saw Snape open his mouth, probably to assure the Hogwarts nurse that everything was indeed
not fine; that Lily and James had swapped positions. Taking a chance, any chance she could get, Lily lightly rubbed her fingers against the bottom of Snape's bare foot. Startled, Snape jumped, though Madame Pomfrey somehow managed not to notice. Rather, she was staring at the wall opposite, having finally noticed the large mural. Meanwhile, despite being extremely ticklish, Snape was much too dignified (at least in his mind, anyway) to burst out laughing, so he held the air in, and, in turn, was unable to inform the nurse of what Lily and James had been doing.
Turning back to her patients, and not seeing anything out of the ordinary, Madame Pomfrey began walking away. Right before she was out of earshot, however, she turned back and stated simply, "Mr. Potter, if you insist on practicing your artistic license in here during your spare time, please take the time to credit your work."
Grinning, James raised his wand and muttered a quick spell. A few seconds later, the words
The Marauders and Lily Evans were added to the masterpiece. Smiling, he questioned, "I think it needs a title, don't you?" Turning to ask Lily her opinion, he found her in an argument with Snape, who seemed to be losing.
"You'll pay for that, Evans. I swear you'll pay."
Lily only raised a single eyebrow skeptically. "In case you haven't noticed,
Snivellus, you're bedridden and I hold the only cure in my hands. So what can you do?"
Flustered, Snape stuttered, "I'll...I'll..."