how does catherine explain to nick the affair of myrtle and tom?

Myrtle is Catherine's sister. In New York Catherine begins to divulge all the "saucy details" of her sister's affair with Tom,

"Neither of them can stand the person they're married to." "Can't they?" "Can't stand them...If I was them I'd get a divorce and get married to each other right away."

Catherine likes to think she is an authority on matters of infidelity and morals. It becomes apparent to Nick that she is vacuous like the rest of these people. She claims, for example that is was Daisy's Catholic upbringing that prevented Tom from getting a divorce even though Nick knows that Daisy isn't even Catholic.