inappropriateness       
noun [ U ] uk/ˌɪn.əˈprəʊ.pri.ət.nəs/ us/ˌɪn.əˈproʊ.pri.ət.nəs/
 不合适,不恰当,不妥当
the fact of being unsuitable, or wrong in a particular situation
  He apologized for the inappropriateness of his comments. 他为自己的不当评论而道了歉。 
 I don't see any kind of inappropriateness in combining ballet with rock music. 我看不出将芭蕾与摇滚音乐结合起来有什么不妥之处。 
 See: inappropriate
 - More examples
 - She suddenly realized the inappropriateness of the jeans and sweatshirt she was wearing.
 - We want people to be aware of the inappropriateness of using test scores as the sole benchmark for student achievement.
 - The TV show has just enough comic inappropriateness to make you laugh.
 - Don't you realize the inappropriateness of a professor dating a student?