Obito's every move was within Ye Feng's divine sense, so naturally, he could also see Obito's hand seals.
At that moment, Obito once again heard Ye Feng's slightly surprised voice by his ear:
"It's actually Fire Release: Phoenix Flower Jutsu!"
Hearing this, Obito immediately looked surprised as well. He had only just learned this ninjutsu and had not told anyone about it yet. Without seeing him form the hand seals, there was absolutely no way to know he knew it. He began to believe Ye Feng's earlier explanation a little more.
So he ran to the doorway again. Seeing Ye Feng still sitting just as he had been before, he became certain Ye Feng had not lied to him.
But this ability really was amazing. Obito hurried over to Ye Feng and kept clamoring:
"Ye Feng, Ye Feng, how did you do that? Hurry up and teach me! I want to learn too!"
Now, however, Ye Feng began to keep him in suspense:
"You really want to learn?"
Obito nodded furiously and said excitedly:
"I do! I do!"
Wearing an expression that said he had hooked him, Ye Feng said:
"Then first tell me, what have you all been doing lately? Why haven't any of you come to see me?"
Obito immediately wilted at that and said quietly:
"Could you ask something else? I really can't tell you that."
Ye Feng pretended not to care and even made to get up and leave:
"If you don't want to learn, forget it!"
Seeing this, Obito grew a little anxious. He hurriedly grabbed Ye Feng, glanced around, and said aggrievedly:
"I'll tell you in secret, but you can't say I told you."
Hearing that, Ye Feng sat back down and nodded:
"Don't worry, I'm not stupid! I won't say anything about you."