“The quality of writing has only gone down, health ” Annie (Cameron Diaz) notes in the new comedy Sex Tape. The statement, made in a discussion about pornography, could also apply to adult comedies today. For every goofy comedy that smartly mocks its genre (22 Jump Street comes to mind), there’s another one that whirls around in the comedy morass hoping to earn a few laughs here and there (Tammy comes to mind there).

Sex Tape is a comedy that falls in the middle. Is much of the humor here coarse and stupid? Yes. But overall is the film funny and did it make me laugh? Surprisingly, that answer is yes.

Diaz stars as Annie, the often inappropriate author of a mom blog where she writes about her adventures raising two children with her husband Jay (Jason Segel). She also writes crudely and explicitly about the sex life she once enjoyed with her then-boyfriend Jay. (“Everything we did was another opportunity to have sex,” she writes.) Of course, as the cinematical cliché goes, once two young sexually active individuals get married and have children, their sex lives are put on hold.

Such is the situation for Annie and Jay, a couple who are still passionate about each other but can’t find the time to have sex.

Much of the humor at the beginning of the story derives from their sexual frustrations and from Julie’s unsparing blog. Twenty minutes into the ninety-minute feature, the duo– hoping to rekindle their romance– film a sex tape which they want to keep private (you know where this is going!) that ultimately ends up in the hands of at least a dozen people who have old iPads that Jay previously gave them.

The film’s most memorable set piece revolves around the couple’s trip (alongside friends played by Rob Corddy and Ellie Kemper) to the house of an executive who is attempting to purchase Annie’s blog. Played by a deadpan Rob Lowe, the corporate executive is a self-absorbed psychotic and elevates his few scenes, which also use Segel’s physical comedy chops to great effect. The scenes highlight what works so well in this feature– Segel and Diaz’s physical comedy for one– and why it could’ve been much much better.

Logic and the film’s ever-diminishing credibility go out the window in the abysmal third act. The characters make decisions there that seem illogical and counter-productive and a last minute cameo isn’t enough to make the ending any less incredulous than it already is.

Director Jake Kasdan has, in movies like Orange County (2002), shown that he can do more with a strong script but the script here is just reasonably good enough for the film to merit a recommendation. Diaz and Segel both seems willing to give the comedy their all and their moments of physical comedy and facial expressions are one of the film’s highlights. It’s just disappointing that the movie obviously relies so heavily on the set piece at its center.

Sex Tape could’ve been a lot better. It’s funny and a reasonable enough choice for a matinee on a Saturday afternoon but this is one tape that will be forgotten whenever better comedies come around.