The Joan character- it's totally okay to commit adultery....
....but only if you are a woman! She is basically all over Tim from the get-go, and the revelation she has a family (and husband) hardly slows her up. She makes adultery seem fun and exciting, and does not display an ounce of regret over her behaviour. Of course, she got married too early, so a girl's gotta have fun, right?
It wouldn't bother me so much if the film was amoral. But ultimately it is about Tim's struggle with whether to compromise his values with a dirty deal. So the film does have a moral core. But Joan's adultery? The morality of that is never even questioned.
So this is the standard for womens' behaviour these days. Don't laugh, the media both reflects and helps create social mores. Now, it seems, a woman's infidelity is more excuseable than a man's. Can you name one movie where a man's infidelity is dealt with so lightly? Sure, plenty of Scorcese's gangsters are adulterers, but in his films we know that we are being invited to revel in the misdeeds of various lowlifes. Joan, on the other hand, comes across as being as sweet and wholesome as apple pie (she just enjoys adultery, that's all).
So, ladies, if you think Joan is just celebrating her sexuality, and is totally justified in her actions, let me say this: maybe this is an example of why men aren't getting married anymore. Who would the average joe rather be- Tim at the convention, having an exciting fling, or Joan's hubby back home, minding the kids and paying the bills like a chump?