sinfully          
adverb uk/ˈsɪn.fəl.i/ us/ˈsɪn.fəl.i/
 有罪过地;不道德地
in a way that is against the rules of a religion or morally wrong
  Even those projects that were successful were sinfully wasteful. 即使那些成功的项目也存在不道德的浪费。 
 They can't perceive that they are acting hypocritically and sinfully. 他们感觉不到自己的行为是虚伪的、有罪的。 
  informal表面诱人实际有害地 
in a way that is bad for you, but enjoyable
  These brownies are sinfully delicious.  这些巧克力蛋糕太好吃了,真让人有罪恶感。 
 The book is wickedly, sinfully entertaining. 这本书很邪门、很诱人,让人很是享受。 
 See: sinful
 - More examples
 - He is born with the capacity to act not only sinfully, but virtuously, by the exercise of his own free will.
 - The desserts are awesomely good: a warm sticky date cake served with ice cream is sinfully rich.
 - Served with plenty of double cream and some seasonal berries, it makes a sinfully good pudding.