in Small House at Allington

Chapter 50 – Mrs. Dale is Thankful for a Good Thing

a slip between the cup and lip

Trollope uses this saying throughout the novel.  It basically means that many things can happen to obstruct a seemingly sure thing.  Mrs. Dale says this to Lily as a caution about talking about the engagement between Bell and Dr. Crofts.  Lily, as we know, is familiar with the slip between cup and lip.  See the commentary for Chapter 9. [KD 2006]