"Chigi! Your relationship is a hypersaccharine concoction of supersaturated snappiness! You guys are sickeningly sweethearts who never argue! Heck, you guys can never be on opposite sides of anything! I'm going to puke out rainbows at this rate! I'm going to get diabetes from all this!" Romano's blood sugar levels had soared through the roof, only worsening his already horrible mood. He made the worst of hyperglycemics look dangerously hypoglycemic in comparison. He may or may not have been jealousHE WAS NOT!
"Lilac, you're the most sickeningly sweet person ever to grace the planet, aren't you?" Lilac didn't seem to catch the insult, and just smiled broadly, apparently under the impression that her 'influence' had reached B as well.
Invoked in Dumbledore's Army and the Year of Darkness, when Hannah tells Neville that her Aunt has some sickeningly cute collectible china witch figurines. Apparently, "It's like trying to eat half of Honeydukes in one sitting. You can feel your teeth start to rot the second you cross the front door."
Harry Potter and the Natural 20: The hamster summoned by Milo's Christmas gift to Hannah is so adorable that "simply seeing it required a Will save, or you were compelled to want to hug it".
Parodied in "Parody of Symphonia", where the particular character achieves the title "So saccharine, she gives you diabetes!"
Sonichu's and Rosechu's children, three small, pudgy, vaguely mammalian creatures named Robbie, Cerah, and Christine. All of their dialogue is written in a sickeningly-sweet baby-talk tone with the "r"s and "l"s replaced by "w"s. Their faces forever wear grins of absent-minded, naïve bliss. These attributes have caused them to become The Scrappy in the series's "fandom," leading to an entire subgenre of fanfiction focusing around their extremely brutal, graphic, and merciless slaughter.
Turnabout Storm has this in-universe. Twilight and Spike get rather embarrassed when they mention a land overseas where weird ponies and humans coexist, those being characters from previous generations of My Little Pony.
Twilight: They're not weird, Spike! They're just... Spike: They're just what? (Cut to G1/G3 ponies) Twilight: Uh... really... happy... Spike: They seem too frolicky for my taste...
"Blech!" spat Bonnie. "Ugh, come on! That was so treacly. Yuck, feel like I need to scrape off all that sugar and honey " she trailed off while swinging a leg over her log. She made a show of scratching at her green fur, rubbing off the happiness of Leroy's ending.
Cori Falls' Rocketshipping fics might as well be called Tastes Like Diabetes: The Fic Series. If Jessie and James aren't angsting for whatever reason or raging about Ash and his friends, they're gushing over how perfect the other one is and how deep and true and everlasting their love is.
Any Samurai Pizza Cats fanfic by authors Merigirl/Pollygirl and/or Phoenix710/Razgriz27 is bound to be both this and Nightmare Fuel all at once, seeing how Speedy and Polly's relationship is some sort of Incorruptible Pure Pureness that's threatened by EVERYONE: Guido, Francine, their jobs, and even random guys on the street making unsavory comments. If you ARE one of those random guys, expect to be berated, followed by the two of them beating you to what can only be described as death+1 (one fanfic had Sppedy using what could be described as a SHŌRYUKEN on a completely random guy!) Not to mention the frequently-inserted Christian themes, sappy songs (many of which are Japanese that's been LITERALLY translated to English with no regard for rhyme or meter), and general "love conquers all" theme that'll make you barf at a hundred paces. And don't even get me started on their daughter Aiko!