In his conversation with Selwyn concerning Miss Kinsman, why is it Frank does not seem to see that Selwyn is attempting to tell him something?

Frank has asked Selwyn to have a conversation concerning Miss Kinsman, but does not appear to recognize that Selwyn is attempting to tell him something, perhaps for several reasons. First, the topic concerns Frank's wife, who has recently left him. Selwyn is cautious in how he approaches a clearly touchy subject. Second, Frank seems wrapped up in his own needs at this point. He is not directing his attention to those of Nellie or Miss Kinsman.