You shouldn't make a commitment that you aren't sure about.
Mary's birthday is coming and a birthday party will be held at her home.
Jill, Mary's sister, wants to make the party more fun.
Jill has practiced a song for a while and sings it in front of the guests at the party.
Jill promises to make a birthday cake for Mary even though it is her first time making cake.
Everyone is surprised by Jill's outstanding performance and enjoy the party very much.
Everyone is disappointed at the taste of the cake.