Little boy singing

In this week my little Theophilus start to singing. He only will sing "twiesker twinkle twinkle little start" and "ABC song" When his mood is good he'll start to sing. But his version of these two songs only he, Eliora and Mommy understand.

When he is singing, Eliora and mommy will follow and guide him these two songs, but he doesn't want ours guide. He'll said "Mommy don't sing" or "U don't sing"