Actress-director Delaney Buffet’s semi-autobiographical dark comedy Adult Best Friends crams in a lot of risque jokes on buddies who are too close to care about borders. The screenplay makes no space for privacy as the two friends, well played, seem to have spent all of their childhood, teens and their 20s teamed together like pilots in a two-seater warplane. The noise outside is so loud that they can’t hear each other.

Of the two, Delaney (playing herself) is the clingier, while Katie (Katie Corwin) is marginally more practical and less dependent on her friend. The problem, if we want to look at it that way, starts when Katie gets a steady boyfriend. How convenient it would have been if the boyfriend, John (Mason Gooding), were just a one-night stand, or even better, a jerk.

On the contrary, John is affable, decent, caring and gracious. Mason Gooding is convincing being a good in a film that avoids that quality.

In a vaguely Jane Austenian twist, Delaney, clogged with jealousy, snubs and belittles John. And tries to convince Katie that John is not right for her. The writing until here is smart. But then it gets smart-alecky, and burdened with the constant anxiety of being casually funny. This is where the writing suffers and finally collapses.

Katie must tell Delaney that she is getting married to John, whether Delaney likes it, and him, or not.

Off they go together, Katie and Delenay, to vacation in a rented apartment whose eccentric landlord oscillates between kinky and creepy.

The humour gets unbearably circumscribed, over-scripted.

The early whoosh of wicked wit whittles down to a whimpering nothingness. Katie and Delany’s vacation, which occupies the midriff of the plot, is filled up with characters looking for some way to be funny; with no real assistance from the writing guild, the humour feels like a stalled car waiting to be towed.

Adult Best Friends does have its moments, though, especially at the beginning when Katie and Delany’s lifelong friendship seems like a bit of a practical problem. How is it possible for two adults to continue behaving like mutually bonded school girls?

I wish the film had not over-populated the plot with characters who keep popping in at him. Katie’s brother (Zachary Quinto) and his psychiatrist wife are just a couple of many characters who seem to be a hindrance in the storytelling.

Less of Jane Austen and more of Woody Allen, Adult Best Friends finally feels like a promise of something special, never kept.