The only good thing to be said for “Perfect Find” is thatGabrielle Unionstars in it. The Bay Area native makes it almost worth seeing. Almost.

For all its many faults, the romantic comedy finds some nice ways to showcase her. Union’s comic abilities get a workout in moments when she must play discomfort and embarrassment, and at other times, the intelligence she brings to her performance lifts scenes that easily might have been dead.

But she deserves better than “Perfect Find,” which pairs a mid-40s professional woman, Jenna (Union),埃里克(Keith权力),一个年轻的man who can’t be more than 25. That’s an unconventional matchup, which could have been a great premise, but the movie doesn’t make the case for Eric as a perfect find or anything close to it. Eric comes off as a spoiled kid, though the filmmakers seem to believe they’re presenting a splendid fellow.

It’s strange. Though the entire story is about a romance across the age gap, the movie is quite cagey about pinpointing the characters’ exact ages. We know that Eric is newly out of graduate school, where he got a master’s degree in filmmaking. And we know that early in the movie, someone says that Jenna is 45, but she corrects them and claims to be 40. However, later, in an unguarded moment, she mentions that she was born in the 1970s. That would make her at least 43, probably older.

This matters because a 20-year age gap is a bigger deal than a 12- or 15-year gap, especially when the age gap isn’t the only thing complicating the romance. Jenna is a designer who used to be on her own, but now is reduced to working for a less-talented former rival, Darcy (Gina Torres). She needs the job desperately, and yet she ends up in a sexual relationship with Eric, who is not only a co-worker but Darcy’s son.

What makes “Perfect Find” a somewhat sour experience is that the screenplay blunders into a situation in which Jenna has everything at stake and Eric has nothing. If Jenna loses her job, she’s broke and probably finished, professionally. If Eric loses his, he’s still mommy’s son.

Likewise, if their relationship goes public, she’s a well-known figure and will be embarrassed, while he’s an unknown entity and will only be elevated. Thus, when he encourages her to relax and let nature take its course, we can’t fully be on the side of romance, because we have no reason to trust him.

Even worse, “Perfect Find” goes on to prove that Eric不应该be trusted. You know how, with most romantic comedies, the lovers have a pointless, concocted argument about 20 minutes to a half hour before the finish? Well, without going into details, “Perfect Find” features a dispute in which Eric behaves in a way that demolishes his character in the eyes of the audience. It’s a destructive scene, and yet it might have worked if the intention were to make an anti-romantic comedy. But it turns out that no, we’re still supposed to see Eric as a swell guy and a good bet. If this were real life, and Jenna were a friend of yours, you’d be telling her to stay away from that guy.

Also unfortunate is the fact that Jenna, despite being touted as an inspired designer, seems to have only one idea in the entire movie, which is to steal outfits from classic films and slap them on models. It’s as if no aspect of “Perfect Find” were thought through because everyone expected that, whatever happened, Gabrielle Union could be counted on to carry the movie.

She almost does, but doesn’t.

Reach Mick LaSalle: mlasalle@sfchronicle.com