These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fetish Fuel: Stealth's outfit is this, in-universe. Cerberus has this with her own outfit.
Fetish Retardant: Common Knowledge in-universe has it that Cairax was zombified when he was having oral sex with zombie Jessica Alba. Ultimately set straight by Hale, who maintains that he just slipped her a little tongue.
Rodney / Legion also uses an undead superheroine for sex. Goes well and beyond past Squick.