Severus Snape nervously shifted his weight from one foot to the other, staring at the currently-blank portrait which usually housed the Fat Lady. Of course, it was just his luck that the Fat Lady would be out on the evening of Lily Evans' fifteenth birthday, when he would want to deliver a present to her. He clutched the present in question behind his back, stretching out a fist towards the portrait.
No, I can't knock on the portrait, it's made of fabric, he thought.
"Lily?" he asked the wall, uncertainly. "You wouldn't happen to be in there, would you?"
There was no response.
Snape stood still for a minute, gathering his thoughts. Suddenly, the portrait swung open, hitting Snape in the face and sending him tumbling backwards towards the gap in the balustrade where the stairs usually were. A hand reflexively shot out and grabbed his arm, preventing him from falling over the edge.
"Oh, it's Snivellus," James Potter said, letting go and pointedly rubbing his hands on his robes, as though Snape's arm were the carrier of some hideous disease he was at risk of catching. "What do you want?"
Snape's right hand flew towards his wand pocket, nearly dropping the flask of potion he had concealed up his sleeve in the process. His left hand scrabbled for it, somewhat held back by the bouquet of flowers he was holding, but he just caught the potion flask before turning up to see James smirking at him.
"Are those flowers for me?" James asked, a mocking edge to his voice.
"No, they're a birthday present for Lily," Snape snarled in retaliation.
James' smirk grew wider, but the humour in his eyes vanished. "Red and yellow tulips with a scattering of lilacs? Do you think you could be any less subtle?" he asked, quietly. Snape froze.
"I don't know what you're talking about."
"Oh, I think you do," James said, seriously. "Look, just don't."
Snape glared at James. "Do you think I could see Lily now?"
James sighed loudly. "Nah, I don't think so, Snivellus. She's not even in the common room," he said, a trace of humour returning to his eyes. Snape peered behind him, past the still-open portrait.
"I can see her right there," Snape pointed out.
"Nooo, that can't be Lily," James responded, his grin expanding to cover his entire face. "Tell you what, why don't I just give these to her for you? I promise she'll get them," he said, barely keeping the laughter from his voice.
Snape considered his options. He could hardly barge his way past James potter into the Gryffindor common room, for risk of being accosted by an angry house of lions, and he couldn't exactly leave it until tomorrow or the flowers wouldn't look so good.
Sighing heavily, Snape reluctantly held out the flowers and the potion. "Fine. Tell her to put the starlight potion in a silver bowl. It will project a story of my telling onto her ceiling."
"Great!" James announced, grabbing the bouquet of flowers and the vial of potion. "So she's to drink the melancholy potion and... what were these flowers again? Rhododendrons?"
Snape's eyes widened in horror. "You wouldn't dare."
"I don't know what you're talking about," James retorted, raising an eyebrow as he withdrew his mahogany wand and waved it, transfiguring the glimmering silver potion into a dark navy concoction and the flowers into several large stalks with colossal spheres of red and blue petals on the ends.
James turned away from the spluttering Snape and lazily turned back into the common room. "See ya, Snivellus," he said, swinging the portrait shut behind him.
Author's notes: For reference, in the language of flowers red tulips mean a declaration of love, yellow tulips mean hopelessly in love, and lilacs mean first love. Very unsubtle, as James pointed out. I think Snape was counting on nobody else but him knowing the language of flowers, so I imagine it was a bit of a shock when James deciphered the meaning on the first go. Also, rhododendrons mean "beware", so considering that and the fact that they would actually make quite a ridiculous bouquet, James really was being rather unkind here.