Size difference (mild)

My character is either naturally small (think hobbit) or shrinks.
This seriously turns yours on because of the power difference, tight fit, etc. Just small enough that being taken deep results in visible bulges, especially after multiple rounds.

Size difference (extreme)

My absolute favorite. Like the above, but much smaller. Doesn't matter if it'd actually be able to fit in real life, screw them like a living, moaning toy without having to worry about hurting them because ~magic/science~. I especially adore scenes where they're hidden in their bigger lover's clothes either to tease the big or as creative bondage for the tiny.

Humanoid monster

Centaurs, fauns, werewolves, tentacle people, naga... Powerful and non-human shaped dicks a happy must. Just no barbs or beast-minded.

Heat

ABO or just nonhuman options where one character goes into a heavy heat because they misjudged the time of year or something else kicked it off so they're around the other character instead of being in their usual isolation. Knotting a plus, even if the top doesn't normally have one (side effect of being around the heat perhaps).

(Offering Nyotalia England, regular England, Duo Maxwell, and Chang Wufei. Reply here or message in private if interested. Most of these can be combined too!)