Is there anything you absolutely refuse to write?
One of the tropes well-known within the romance industry is called May/December relationships. This is merely a cutesy way of referring to a pairing or couple where one-half is older/more experienced (in the December of their life) and the other is still in the springtime of their youth.
In general these relationships can be depicted in adorable or serious ways that show respect for real-life people in similar relationships.
However! There are extreme cases where this May/December type of relationship is exaggerated into more of a January/December situation, where it feels abusive or disturbing in how they depict the manipulation or grooming of young people (particularly girls, though boys are not spared.)
These are cases when you have a teen (barely adult or almost adult) with a person (usually male) who is extremely older. Think of age ranges such as: 16/100 or 16/500 or 16/timeless. [A few examples of these types of relationship can be found in books such as Twilight, An Enchantment of Ravens, or Spin the Dawn.]
These depictions are a byproduct of the misogynistic tendencies of older men to want young women (or literal girls) in place of someone their own age. Because gay romance started within the romance industry, which was heavily dominated by women writers at the time (still is, but there are certain trends that look encouraging to see more diversity), this same concerning extremist age gap has strayed into gay romance slightly.
Regardless whether we want the responsibility or not, an author’s work can and does have an influence over those who read it. So the proliferation of this extreme side of this trope can have adverse effects (this is particularly true of within the YA arm of publishing because now you’re purposefully targeting the young.)
I don’t think it’s healthy for the young to think of a person 100/500 years above them as attractive. That type of relationship is, at best, concerning, at worst, grooming and controlling. So while I’m not adverse to the typical May/December relationships in any way, I will never write a high-school-aged girl/boy falling for someone a significant amount older. (Or, if I do, I shall never depict it as a healthy relationship.)
And I seriously wish people would stop writing those stories.