Facebook couple
Two people who aren't even together but they're too busy messaging each other about how much they love each other to notice that they're both cheating on their actual partners.
'My love for you is eternal', but they're both still talking to their exes behind each other's backs.
'They're like a couple on Facebook, but in real life they're just trying to avoid getting caught.'
'They write sweet messages, but when they meet their real partners, it's all drama and drama and more drama.'