I've always liked human x non human romances (to an extent) but it's usually the seme thats not human. I've already read:
K's Secrect
My Purrfect Boss
Uninvited Guest on My Shoulder
There was a human seme x vampire uke but I can't remember the name. The seme had black hair and the uke had white hair. The seme was an artist or sculptor maybe. The seme would let the uke drink his blood but the uke was reluctant to do so after seeing the seme take a bunch of supplements due to all the blood loss. I remember it being pretty angsty.