Who is Collin from London Transports and what is their importance? London_Transports English & Literature Collin | London Transports

Nan's long-time lover who shares her flat and its expenses but has no intention of marrying, despite what Nan hopes and believes, Colin often makes cruel remarks about Nan's clients. Particularly hurtful is his calling Shirley a beach ball and a "technicoloured Moby Dick" (p. 301). Nan reprimands him, explaining that she feels protective about Shirley. Nan asks Colin to pick up some green eye shadow for Nan, since he is in the trade, and he labels the bag "Green eye shadow for burly Shirley" (p. 303).