"I'll be careful," Aster promised. He was honestly very curious about the tail and how it worked, but at the same time, he wanted to respect Timmy; he didn't want to ask questions about something that was ultimately a painful subject for the other boy. It was like asking someone how they lost an arm, or something. Just rude. Even though he was an inquisitive kid - to the nth degree, in a lot of cases - he would let it be. If Timmy told him, he told him. If not, he would leave it alone.
"Timmy," he said warmly, and he pulled back enough that he could his hand under the Hufflepuff's chin and gently coax his face upward so Aster could meet his eyes in the gloom. "It's all right. This is new and...I'll learn." His fingers trailed back into the mop of Timothy's hair. "You're so bloody cute. I...really wanna kiss you, actually," he said with a sheepish sort of grin.