She broke into a wide grin, fully aware that this was incredibly immature but determined to test it out anyway. "Don't look so worried, Wayne! It's not corrosive acid." Well, maybe to a stomach, in extreme amounts. "I could clear it up with a swish of my wand."
Eloise didn't leave Wayne much time to change his mind. She placed the cup (lid still intact for the sake of her friend's reservations) about a foot from the headboard. A moment later she was on her feet at the other end of the mattress, not quite on center. One could imagine that she had been a bed-jumper as a child. "Right."
For a few seconds, Eloise gave a few tentative jumps, and found the sensation entirely unlike any other mattress she'd done this on. The cup, for its part, remained stubbornly upright. A few bolder leaps seemed due, and after a short while Eloise was convinced that this was, in fact, a modern miracle. Plopping down again, she leaned over and put the cup back down on the floor before returning to her original position.
"You were right, this mattress is perfect. I think it's only a matter of time until we hear of it solving world hunger and ending wars."