A new Hobby. Dad's or Hayden's???

Dad and Hayden went to a Hobby shop to look around. Dad and Hayden found a beginning model airplane to build. Dad thought Hayden would love this. Dad also did not realize how much the little sister would love to help. Dad and Hayden started building. Dad continued to build. Hayden watched and oh and ah over the airplane. Dad is a proud parent of Hayden's new hobby. Who's new hobby you think???