On-screen chemistry in a romantic comedy can be pretty dicey  — you never really know how audiences are going to react when you randomly throw two stars together, no matter how beautiful they may be. In the case of “The Wedding Singer,” the 1998 rom-com smash, it worked out great. Somehow, Adam Sandler (that guy from “Happy Gilmore” and “Saturday Night Live”) and Drew Barrymore (that woman from “E.T.” when she was little) clicked immediately, and many credit them for the movie’s success.

Now, about 14 years later, Barrymore and Sandler reunite again for the family-friendly”Blended” as executives are no doubt hoping to tap into that late-’90s nostalgia to sell tickets to the flick. After all, with this type of film, you’re not selling the actual movie — you’re selling the star power. Unfortunately, there’s a danger in doing that: These kind of reunion movies (starring two former on-screen love interests) are generally a letdown; especially lately, when it reminds people how far the romantic comedy genre has fallen.

It’s not that “The Wedding Singer” was an especially amazing piece of cinema. But the charming movie was also boosted because it happened to be in a glorious age of frothy rom-coms, when films like “Notting Hill,” “You’ve Got Mail,” “Never Been Kissed,” and even teen favorites “10 Things I Hate About You” and “She’s All That”  hit it big at the box office. Alongside all of those, “The Wedding Singer,” in which Sandler played a wedding singer dumped at the altar and eventually found love with Barrymore’s sweet character, became a similar nostalgic classic.

Now, “Blended,” which pairs the duo together for a third time (in addition to the cute-but-forgettable “50 First Dates” about a decade ago), will simply never come close to adding up. The movie stars Sandler and Barrymore as two polar opposite single parents who despise each other, although obviously they wind up with their kids on the same African safari and things spiral from there. Reviews range from solidly okay to scathing.

That’s part of the problem. “Blended” serves to further illustrate how the rom-com genre has plummeted over the years, with many declaring the genre officially dead. It’s no secret that former romantic comedy box office powerhouses such as Julia Roberts and Reese Witherspoon can’t open movies like they used to. And though Sandler and Barrymore still spark on camera (even if their material in his movie is a far cry from their former adorable scenes in other films), the subject matter is still solidly mediocre.

At the end of the day, reviews don’t really matter: Sandler and Barrymore are starring purely for their box office potential, and banking that people who saw movies like “The Wedding Singer” in the late ’90s wants to see their favorite romantic comedy duo back together; and this time, they’ll bring their kids.

Maybe they will. But likely those people will be disappointed by comparison, which cheapens the whole experience. And as that happens time and time again, it further results in battering the rom-com genre as a whole — which is already, at this point, pretty much beaten down.