Topics/themes/tropes (kinda general, not only one fandom specific):

• noncon
• whipping
• power imbalance
• age and/or experience difference
• language or accent differences as a plot point
• D/s that feels natural, no explicit consent checks
• sadism/masochism. Again, see above for how
• hair-pulling
• kissing
• open or half-open shirts, tight jeans
• gradually finding safety in each other
• dealing with the aftermath of noncon/abuse
• rivals to lovers
• hurt/comfort
• kissing
• communication, banter, winks, smirks

Smut and dark likes:

• fingers to mouth
• blowjobs
• cum trickling from mouth
• rough intimacy and sex
• aftercare
• straddling
• riding
• face to face sex
• pushing knee between someone's legs
• displays of power and domination
• calling someone "mine"
• biting (including vampire biting smut)
• knife play
• mentions of blood
• restraints, ropes, handcuffs
• in dark fic: mock tenderness
• backtalk making things worse

AU themes I love:

• brothel or male prostitution AU
• vampire AU