I've always got along very well with little kids and I'm sure I won't disappoint you.

disappoint 由前缀 dis-（表示"否定、相反"）和动词 appoint（任命、指定）组成，字面意思是"使任命落空"，引申为"使失望"。这个词表示"未能达到期望或让某人感到不满意"。