Watched it tonight. I agree. They didn't plausibly establish why Alice Faye would be drawn to Dana Andrews in the first place. Maybe we were meant to sense some "core of decency" in his grifter character, which she and she alone of all the characters could see, but I don't think the audience could see it!
Eddie Muller has said that it was re-edited in a way that made Alice Faye's character less plausible. But the Dana Andrews character seems SO unlikeable throughout. Only a really charming sexy likeable actor like, let's say for that time period, Cary Grant on the one hand and Robert Mitchum on the other and Edward G. Robinson on the third, , could have played a character who seems to be so clearly on the make throughout the film, and make us believe that he secretly is a great guy. Dana Andrews - hell no. Why not just go for Tom Neal and be done with it.
It has been shown before, many times. Thursdays are pre-code days most of the time and of course there's always Joel McCrea's birthday or something like it. So many of McCrea's early films were things like this where he played a weak rich playboy who can't keep his dick in his pants.