Kind of like fashion itself, we don’t really care whether “Zoolander 2” is any good. We go because it is silly fun.

The original Zoolander, released in 2001 just after the attacks on 9/11, was based on shorts Ben Stiller created for the VH1 fashion awards. It was moderately successful on release but has become a big hit on DVD/Blu-ray and an enduring cultural touchstone. It’s the kind of movie that is best watched at home, with friends who know exactly where the punchlines and star cameos come in, or while sick in bed recovering from the flu when you’re not quite up for binge-watching something that requires more than half your attention.

I suspect the same will happen with this 15-years-later sequel, again directed by Stiller, who stars as the dimwitted supermodel of the title and co-wrote with Justin Theroux, Nicholas Stoller, and John Hamburg. The script relies heavily on the audience’s affection for and knowledge of the first, with more winking references to the original than attempts to be funny about the current state of fashion and the industry.

In the first film, Derek Zoolander plans to build a book-shaped center called The Derek Zoolander Center for Kids Who Can’t Read Good and Who Wanna Learn to Do Other Stuff Good Too. After that film ended, we are told through clips from television news shows (Katie Couric, Jane Pauley, and Jim Lehrer are among the first of an avalanche of what-is he/she-doing-in-this-movie celebrity cameos) that after it was built the building immediately collapsed, killing Zoolander’s wife (Stiller’s real-life spouse, Christine Taylor) and injuring Derek’s rival-turned BFF, Hansel (Owen Wilson).

Partly because he was so distraught, but mostly because he is an idiot, Derek was unable to take care of his son, Derek Jr., and he was taken away by Child Protective Services. Derek announced at a press conference that he was retiring from modeling to become “a hermit crab.” Hansel, his face scarred from his injury, also retreated from the world, to live in the desert (well, Malibu) with an 11-person assortment of consorts he refers to affectionately as his orgy.

But then a nefarious villain is killing pop stars, who die with what appears to be Derek’s famous Blue Steel look on their faces. When Justin Bieber is killed (with time for an Instagram filters joke), Interpol’s fashion division, led by a former swimsuit model (eternal beauty Penelope Cruz) decides that they need Derek’s help to solve the crime.

There’s a lot of fan service here, which can seem stale to those who know the first movie well. But as a lukewarm fan of the earlier film, I found myself being a lukewarm fan of this one, too. The dumb jokes (both those about being dumb and those that actually are dumb) and grotesqueries are no funnier but no less funny. The storyline (Will Derek be reunited with his son? Will Hansel be a father to his various upcoming babies? Will Will Ferrell’s Mugatu destroy whatever it is he is planning to destroy?) is weak, but it is a hoot to see the fashion dream team (even Anna Wintour!) playing themselves with such good humor. In fashion terms, it’s a cheap knock-off, but sometimes that’s all you need.

Parents should know that this film includes very strong content for a PG-13 including very crude sexual references and brief graphic sexual humor, mostly comic violence with characters injured and killed and some disturbing images, and brief strong language.

Family discussion: What are the most important messages we receive from the fashion industry? If they make a “Zoolander 3,” what celebrities would you like to see included?

If you like this, try: the first “Zoolander”