Harry says no because Harry thinks that Poby doesn't like his singing.
Pororo_ENGLISH3_3_Pororo_ENGLISH3_3_ep4_70 Pororo_ENGLISH3_3_Pororo_ENGLISH3_3_ep4_71 Pororo_ENGLISH3_3_Pororo_ENGLISH3_3_ep4_72 Pororo_ENGLISH3_3_Pororo_ENGLISH3_3_ep4_73