[I wrote this late at night after seeing a headcanon about wizards not knowing shit about muggles performing their own "magic". Disclaimer: Idk shit about illusion or card tricks or whatever and i didn't do any research because it was late and i was tired, also english isn't my 1st language so deal with it]
"Nope. I don't believe you."
"Then please, explain to me how," Sebastian said and put his hand up, showing Jim it's empty and moved it close to Jim's ear, "did I get a sickle from behind your ear?" He smiled and showed Jim the silver coin.
Jim's eyes widened in shock and he grabbed a coin to examine it.
"You used magic," Jim said, still examining the sickle.
"Nope. My hands were empty."
Jim huffed and gave Sebastian his sickle back.
Jim and Sebastian were in Gryffindor common room. About ten minutes ago, Sebastian told Jim he could perform magic without his wand. Jim didn't believe him, so for the past few minutes Sebastian was showing him tricks with coins. For Sebastian it was entertaining, as he knew Jim didn't know about muggle "magic". For Jim on the other hand, it was frustrating.
"I refuse to believe you muggles have magic of your own," Jim said, still not convinced.
"Jim, I showed you like 5 'spells' with a coin," Sebastian chuckled, finding Jim's stubbornness cute.
"Yes, only coin. You'd have to show me more."
Sebastian, without a word, went up the stairs to his room to get a pack of cards. When he got back, Jim rised an eyebrow, looking at the cards questioningly.
Sebastian unpacked the cards and placed a whole deck in his hand. He performed a quick card spring, laughing at Jim's shocked face, and shuffled the cards. Then, in one smooth motion, he put the cards in a fan, with their backs up.
"Pick a card and don't tell me what it is," Sebastian said, pure smugness on his face. Jim, hesitantly, picked a card which turned out to be the seven of hearts. "Now remember this card and put it back in the deck," Sebastian instructed and Jim did just that. Then Sebastian performed another card spring and shuffled the cards again, just to put them in a fan again.
Jim observed, looking for any tricks.
"Was that your card?" Sebastian asked, pulling out two of spades.
Jim laughed, "Nope. You got it wrong, tiger."
Sebastian grinned and pointed at the chest pocket of Jim's shirt, "Check the pocket."
Jim's smile faded as he checked the pocket.
He pulled out the seven of hearts.
He gasped and looked at Sebastian, surprised, "Wha- how??"
"Magic," he said and took the card from Jim's hand to put it back in the deck and then in the box. He hid it in his robe pocket and sat down on the sofa, still smiling.
Jim's brain was trying to figure out how Sebastian did these things. He knew for a fact that muggles don't have any magic abilities, or at least most of them, so how?
He sat on Sebastian's lap, his knees next to Sebastian's sides, and pulled the box of cards out of blonde's pocket and started examining it, not aware of Sebastian's questioning gaze that slowly turned into an amused smile.
Jim hated not knowing, both about things and how to do things, so it was understandable that he was frustrated. He huffed and took the cards out, wondering how the hell did Sebastian do that card spring.
He tried to do it himself, but the cards flew around and made a huge mess, making a few Gryffindor's that were in the common room with them laugh. He gave them The Look, and they stopped laughing immediately.
"Jim, Magpie, you aren't going to do shit like that," he said with a fond smile and – with a help of actual magic – he picked up the cards and handed them to Jim. "You gotta find a good way to hold them. It's all simple physics."
Jim rised an eyebrow, "So there's no magic?"
"Obviously," Seb laughed. "It was an illusion. Years of training my hands. All of it. But you could call that 'muggle magic'."
Jim stared at the cards as a grin spread on his face, "What else can you do with those hands?"
Sebastian put his hands on Jim's hips and leaned in to kiss the Slytherin's neck. "I can show you if you want.