'''Basic Trope''': A character believes their significant other is cheating on them.
* '''Straight''': Alice sees her boyfriend Bob and his friend Claire alone together and assumes he's cheating.
* '''Exaggerated''': Bob strikes up an innocuous conversation with Claire, which arouses Alice's suspicions.
* '''Downplayed''': Alice sees Bob staring at Claire's chest and assumes he's blatantly checking her out. Really he's just astonished by Claire's ugly shirt.
** Alice's previous boyfriend cheated on her, so she's more likely to assume other guys are cheating.
** Or Bob has a known history of cheating on his girlfriends, but is working hard to amend his ways.
** Bob and Claire make out in front of Alice - and she doesn't suspect a thing.
** Alice suspects Bob of everything but cheating, only to learn that he was having an affair with Claire.
* '''Subverted''': It turns out Bob really ''was'' cheating on Alice.
* '''Double Subverted''': With her clone.
* '''Parodied''': Alice, of all people, turns out to be the other woman.
* '''Zig Zagged''': However, it turns out Bob really WAS cheating on her, with Alice's sister, who asked Claire to tell Alice nothing happened between Claire and Bob.
* '''Averted''': Alice doesn't assume Bob is cheating.
* '''Enforced''': "Alice and Bob are happy, right? [[TrollingCreator We can't have that!]]"
* '''Lampshaded''': "I hope Alice doesn't think there's anything between us!"
** When Bob believes Alice is losing interest in him, he starts hanging around with Claire to make her jealous.
** Claire starts smooching Bob when Alice shows up, deliberately trying to drive them apart.
* '''Exploited''': Charlie tries to confirm Alice's suspicions. So that she will leave Bob & [[LoveTriangle start going out with him]].
* '''Defied''': Bob refuses to even do anything that could be construed as romantic with any other females, because he doesn't want to make Alice assume anything.
* '''Discussed''': "It's all a mistake! I wasn't cheating!"
* '''Conversed''': "Oh, another plot where she thinks he's cheating on her."
* '''Deconstructed''': Alice's constant suspicions start to derail the relationship and end up destroying it, as the constantly-faithful Bob decides he's had enough of it.
* '''Reconstructed''': Claire is eventually able to prove Bob's innocence, leading Alice to try to win Bob back over and repair their relationship.
* '''Played For Drama''': Alice sees Bob with Claire and jumps to the wrong conclusion--that they're having an affair. She then takes her revenge by setting out to destroy Bob's reputation, leaving him broken and friendless. It's only then that Claire manages to convince Alice that there was no affair. When Alice realizes the truth, she tries to apologize to Bob, but it's too late as Bob is too broken to want anything further to do with her.
Honey, I can explain the LipstickMark, the bra in my bed, and the photos! Just go back to MistakenForCheating!
%% Optional items, added after Conversed, at your discretion:
%%* '''Implied''': ???
%%* '''Plotted A Good Waste''': ???
%%* '''Played For Laughs''': ???