I've got a few things that make me roll my eyes.
Love triangles. I'm not saying they can NEVER be done well - I'm just saying that they rarely are. Too many of them make the central character seem like an indecisive idiot, too many of them prolong their own existence by turning the central character into a lying indecisive idiot, and far too many of them come pre-packaged with the obvious right answer. As in, from the very start, you can tell which love-interest the author wants the central character to go with, because they turn the other option into someone who is good-looking but also shallow and manipulative, or something like it.
... Also, they're less love-triangles and more love Y's. It's almost always a case of the central character A being kind of in love with both characters B and C and unable to make a choice. It's rarely A being in love with B who is in love with C.
I like them even less when they're a last-moment introduction into what began as a simple story of two characters falling in love, either on the cusp of the two actually getting together, or when they've been together for a while, just so the author can drag out the story for longer.
I've actually got one of these kicking around in a story-universe I haven't done much with yet. =D They end up settling into a steady plolyamorous relationship and even have a kid together.
Heteronormative gender-roles in LGBTQ+-relationships. I roll my eyes so hard they nearly roll out of my skull when I come across a BL story where you've got one small, physically weak, cry-baby character as the "bottom", and a bigger, buffer, more masculine character as the "top" (because we all know that gay men are defined by what type of position they prefer in bed, and that this is immutable and set in stone and can never be changed or experimented with).
I'm sure there ARE IRL gay relationships that do fall into this pattern, but it's not universal, and in fiction it's a boring cliché.
Also, when you do slot your gay characters into this heteronormative pattern, you're signalling some pretty weird ideas about connecting femininity with weakness and uselessness which I'm not, uh, particularly fond of. The same goes for using this weird archaic heteronormative gender-role bullshit in any other relationship on the LGBTQ+ spectrum.
See also: Turning women in BL-comics into screechy romantic rivals, just to make your gay OTP look amazing.
Romanticising rape and abuse. The fastest way to make me nope right out of a romance comic is when one party sexually harrasses or outright rapes the other party, and the author assures me that I'm supposed to think this is an expression of love or affection or of the perpetrator just losing control of themselves because they were SO overwhelmed by their feelings for their victim.
No.
Not only does this romanticise and attempt to normalise sexual harrassment/rape, but it also places the blame for it squarely on the victim. Oh, they were just so pretty that their rapist lost control. Oh, their rapist can't be blamed for it and must be forgiven - they did it out of love!
NO.
Likewise with any kind of abuse. I'm tired of seeing victims of it in fiction dry their tears, accept their abuser's verbal assurance it won't happen again, and just shrug it off.
The big misunderstanding-trope. Much less toxic than the tropes listed above, but the Big Misunderstanding (TM) that turns up in SO MANY ROMANCES annoys the heck out of me. Especially ones that can be easily solved by the characters SPEAKING TO EACH OTHER WITH ACTUAL WORDS, LIKE HUMAN BEINGS DO.
I think the only Big Misunderstanding story I genuinely like is Pride and Prejudice, where the misunderstanding between Mr Darcy and Elizabeth relies on a.) Elizabeth not knowing him well and having had no chance to build any trust for him, b.) Mr Darcy being kind of a dick when they meet the first couple of times, and c.) society restricting the ways they can interact with one another. And you know how their big misunderstanding is solved? BY COMMUNICATING, and by allowing the characters time to consider what has happened, grow as people and change their minds.
I've got an asexual character in a oneshot I'm working on right now! It'll start posting in December. :3 It's not a romance story, but if I DO somehow find the time, I'm hoping to do a Valentine's Day sequel, which is going to be more romantic.
I think what Jess means is that there should be more relationships in fiction between characters who are asexual. It's not about staying G-rated - it's about there existing people in real life (hi, I'm one of them!) who don't experience sexual attraction to anyone. It's not a choice, like celibacy or abstaining from sex - it's simply that we don't want to have it.
Asexual people are as different from one another as any people of other sexualities - some of us don't want to have sex at all under any circumstances, some people are okay with kissing while others aren't, some people have sex sometimes but have a sex-drive so low that it rarely ever happens, etc., etc.
There are characters in fiction that seem disinterested in sex, but whenever they turn up, I start the mental countdown to when they either a.) get "fixed" by falling in love and suddenly discover that they DO want to make out with/have sex with their love-interest, or b.) get made fun of for being a nerd who can't get any.
.
.... This big old post makes it seem like I hate romance stories. I don't! I read plenty of them! It's just that I tend to prefer ones where the characters fall in love because they genuinely like each other, where abuse isn't normalised, and where being different isn't something you have to fix. Give me characters who bond over shared interests or experiences! Give me characters who accidentally stumble into small adventures with each other and at the end of them realise that they might be falling in love! Give me couples who spend rainy days together, and bake cakes, or realise they can't have kids because [reasons] and decide to adopt a cat instead, or whatever.
Give me romances between people who aren't teenagers. Give me the love-stories where love isn't earth-shattering or the be-all and end-all of the universe. And give me romances where love IS earth-shattering, but make me believe it's actually there, and not just the characters mouthing the words. Don't make someone the designated love interest - make them a person your main character can actually find something to love in.