Warner Bros. Pictures

Science movies can be fun and fascinating, but they are seldom if ever sexy. When Hollywood sets its sights on a scientific topic, it's usually to highlight the danger or drama of a particular worst-case scenario -- and those scenarios are often disturbing, terrifying or otherwise off-putting.

In other words, they're not the kind of movie you want to see with a date at a revival screening, or rent for that romantic movie night at home. Nothing kills the mood faster than hard science conjecture on, you know, viral infections and gene-splicing and theoretical physics. In the interest of romance and consumer advocacy, here are some science-based and sci-fi films you definitely don't want to see on a date night.

Science Vs. Fiction: 'Elysium'

Jude Law fights pandemic with propaganda in a scene from the 2011 thriller "Contagion."Warner Bros. Pictures

"Contagion," director Steven Soderbergh's profoundly unsettling 2011 thriller, depicts a global pandemic caused by a pig/bat hybrid virus that jumps species and starts infecting humans. As the DVD extras reveal, the filmmakers worked closely with consulting epidemiologists to make the movie as realistic as possible. In fact, the film was based on an actual outbreak Malaysia in 1999 that killed more than 100 people.

The perils of "Contagion" as a date night movie are clear. You don't want your significant other thinking about infections, bodily fluids and disease vectors. In fact, after this movie, you won't even want to touch a doorknob.

'World War Z': The Revolt Will Be Fact Checked

Fears of overcrowding and urban poverty lead to drastic measures in the 1973 sci-fi hit.  Metro-Goldwyn-Mayer

Loosely based on an obscure 1966 sci-fi novel, "Soylent Green" was a relatively low-profile genre picture that became a surprise hit in 1973. The film, set in a dystopian New York City circa 2022, addressed contemporary fears about pollution, overpopulation and poverty. In the infamous final scenes, it's discovered that the government-issued protein rations are not made from plankton, as advertised. The revelation prompts Charlton Heston's immortal line: "Soylent Green is people!"

This is clearly a bad recipe for any dinner-and-a-movie agenda, so take Chuck's advice and avoid "Soylent Green."

The Science And Fiction Of 'Oblivion'

Ambitious engineers accidentally invent a time machine in the mind-bending "Primer." ThinkFilm

This microbudget indie from 2004, written and directed by Shane Carruth, was made for a mere $7,000 and went on to win the Grand Jury Prize at the Sundance Film Festival. Carruth, a mathematician and engineer, based the movie around advanced time travel theory and the story is dense with technical jargon and mind-bending theoretical physics. After the film debuted, obsessed fans took to the Internet to create impossibly complex technical breakdowns of the film's parallel timelines. (Like this one.)

And that's the problem with "Primer" as a date movie. Forget about romance, you'll spend all night trying to figure the thing out and making giant wall charts about temporal paradoxes.

A gene-splicing experiment goes sideways in the creepy sci-fi cult sensation. Warner Bros. Pictures

The genetic engineering cautionary tale "Splice" is one of the most daring sci-fi films in recent years. The film follows two genetic engineers, played by Adrian Brody and Sarah Polley, as they perform a decidedly ill-advised gene-splicing experiment. The result, a hybrid human specimen named Dren, is among the freakiest creations in all of science horror cinema. In fact, the movie's storyline was so weird and bold that studio executives initially refused to release the film.

In any case, "Splice" is a kind of worst-case scenario in regard to reproductive issues, and a definite mood killer.

Know Your Giant Monsters!

A "facehugger" -- one of several distinct phases in the alien lifecycle -- embraces its victim. 20th Century Fox

Director Ridley Scott's 1979 freakout "Alien" is rightly regarded as one of the most important and influential sci-fi films in movie history. While the film has plenty of future science conjecture to chew on -- Deep space mining! Stasis pods! Androids! -- the really interesting stuff involves the alien creature itself. The design for the alien was inspired by the work of Swiss surrealist artist H.R. Giger -- in particular the lithograph Necronom IV -- and director Scott specifically chose the design for its scary sexual overtones. This fit with the storyline in which the alien "impregnates" its victims with an embryo that eventually bursts free, killing the host.

In other words, "Alien" is built around subliminal imagery designed to terrify viewers and equate sex with grisly death. So, yes, not a great date night movie.

Into Reality: Top Star Trek Warp Speed Concepts

The 1971 space germ thriller terrified audiences upon release. Universal Pictures

When "The Andromeda Strain" hit theaters in 1971, it was for many audiences their first introduction to the idea of biological weapons and germ warfare. Based on the Michael Crichton novel, the film follows the path of destruction left by an alien microbe brought back to Earth on a crashed military satellite. Scientists study the microbe in a secret underground lab called the Wirefire Complex, which is all about rubber suits and elaborate decontamination protocols.

These passages, combined with the film's chilly and cerebral tone, tend to disrupt the date night vibe. Then there are the graphic scenes of people dying horribly from rapid, lethal blood clotting.

Going Viral: Pandemics In Fiction And Fact

Ethan Hawke and Uma Thurman are made for each other in the world of "Gattaca." Columbia Pictures

Another criminally underappreciated sci-fi film, director Andrew Niccol's 1997 "Gattaca" deals with both the hard science and social science aspects of human genetics technology. In a near-future setting, a kind of popular eugenics system allows parents to genetically profile embryos prior to implantation, selecting for optimal hereditary traits. Uma Thurman and Ethan Hawke -- surely two of our most genetically gifted movie stars -- must navigate a scary future society in which destiny is determined by genes. The name of the space agency in the film, Gattaca, is composed of the letters GATC -- or guanine, adenine, thymine and cytosine, the four bases of DNA.

While there's nothing particularly gross or disturbing in "Gattaca," the very subject matter -- and the presence of those two elite specimens Thurman and Hawke -- might lead a romantic interest to start questioning your own genetic potential.