Bloodfang has 2 sex scenes until now, one if you use his bed in the ToB's (and high enough estrogen/romance with him), and another if you have high estrogen in Floor 13's inn (if you get a royal room and have high enough estrogen, you should be fine based on your post). Planning to add more in the future.
(actually I have already made another that triggers in the player house of Floor 14, Theodoxa, which isn't available yet).
He's a pretty recent addition to the romancable characters, so it's to be expected he's a bit lacking in content for now.