Any movie involving two romantic leads requires a healthy amount of chemistry and the directors often go to great lengths to make sure that's the case.
In Derek Cianfrance's brilliant, Blue Valentine, for instance, he made Ryan Gosling and Michelle Williams stay in the same house for weeks to ensure they had a thorough understanding of what it's like to be madly in love but also get on one another's nerves and it ultimately spawned two spellbinding performances in one of cinema's most heartwrenching flicks about the harsh realities of long-term love.
In other cases, however, the performances haven't been as good, and though the acting might have been to an acceptable standard, the lack of chemistry can make for an incredibly uncomfortable viewing experience.
Here are 10 toe-curling examples.
1. Beyonce & Idris Elba- Obsessed
There's no questioning the talents of these two artists, but when they teamed up in the 2009 flick, Obsessed, it was evident that both felt uncomfortable around each other.
In the British actor's very own words, he admitted that it was "strange" kissing the Halo hitmaker.
2. Kristen Stewart & Robert Pattison- Twilight
They may have dated in real life, but Kristen Stewart and Robert Pattinson couldn't ever seem to convince anyone other than teenage girls and Mormon moms that their relationship was any good. In fact, it sucked.
Yes, the pun was awful and unnecessary, but it did suck, and most critics agreed that it was the performances of the leads that made it suck even more.
3. Hayden Christensen & Natalie Portman- Star Wars prequels
You probably don't need us to tell you the Star Wars prequels aren't worth seeing again, and like with Twilight, a big reason stemmed from the static performances from its leads, Hayden Christensen and Natalie Portman.
Though good actors, their wooden performances came across like they were two high school seniors forced to take an acting credit to boost their chances of getting into an Ivy League college.
4. Dakota Johnson and Jamie Dornan
The 50 Shades phenomenon shows no sign of slowing down, with both films making hundreds of millions of dollars worldwide to add to the already record-breaking book sales of the same series, but the two leads, which were inspired by Meyer's Twilight characters, are equally as bad.
The reason for such a lack of chemistry is probably because of Jamie Dornan and Dakota Johnson's inability to get on, despite performing scenes of a highly erotic nature. Perhaps E.L. James should have told them to spend a month living together in a room full of butt plugs. Just a thought...
5. Jennifer Lopez & Ben Affleck- Gigli
This film was truly awful, and the performances from star actors Jennifer Lopez and Ben Affleck were no different.
Rightly, both were awarded Razzies for their respective roles, which we hoped would have put an end to their acting careers. Unfortunately, that hasn't been the case.
6. Pierce Brosnan and Teri Hatcher- Tomorrow Never Dies
One of the worst Bond films adapted from Ian Fleming's powerful cannon of works, the chemistry between Brosnan and Hatcher is beyond terrible, and we can hazard a guess as to why that may have been the case.
According to the man himself. Hatcher regularly turned up to set late. “I got very upset with her,” Brosnan revealed to the Italian edition of Vanity Fair. “She was always keeping me waiting for hours. I must admit I let slip a few words which weren’t very nice."
It turns out, however, that the future Desperate Housewives star was pregnant and regularly nursing morning sickness.
7. William Baldwin and Sharon Stone- Sliver
Any film involving William Baldwin, A.K.A.; the least talented of the Baldwin brothers is bound to be a stinker, and the 1993 thriller, Silver, was no exception.
Indeed, Baldwin's cinematic career (yes, he actually had one) never really recovered after his dismal performance. But Stone wasn't at her best either, perhaps because she was annoyed with the talent put in front of her. Allegedly, Stone took great comfort in torturing Baldwin and even bit his tongue so hard that he was unable to speak for a week!
8. Benjamin Bratt and Halle Berry- Catwoman
You'd think the idea of acting opposite a latex-clad Halle Berry would be enough of an incentive to fully embrace the role and give it your all, but Benjamin Bratt's character, Detective Tom Lone, didn't seem to be all that interested.
On behalf of all men, Benjamin, you took a once-in-a-lifetime opportunity at wooing the most beautiful woman alive and totally blew it. A poor performance. So poor in fact, we also blame it for Berry's equally uninspired outing as Catwoman.
9. Katie Holmes and Christian Bale- Batman Begins
Christian Bale is a terrific actor, but he was let down by a rather flat performance from his co-star, Katie Holmes.
After all, Batman is supposed to be an independent bachelor afraid of letting anyone too close, so you'd think his love interest would be exciting. But no, she wasn't and was unsurprisingly replaced by Maggie Gyllenhaal for the sequel.
10. Olivia Wilde and Daniel Craig- Cowboys & Aliens
Both are brilliant actors, but even Wilde and Craig's natural talents couldn't create a clear-to-see chemistry in a film that was panned by both critics and cinema-goers.
Stick to wooing Bond Girls, Daniel!