Did you get the scene on the way to the mine where he has you give him oral, i didnt get that scene until i had gotten then northcrest guards reputation to a certain point, Dulrag will make a comment how popular you are... after that just ignore him putting his hand then im not sure if the second guard interaction affects his heart i went with it, and in the cave protect him, eat him out either once only or twice only not entirely sure (i did twice) and then give him the max amount of crystals you can. That should give you the heart.
deleting cause I just saw you figured it out lol. but wanted to mention, Feminine juice only makes you smell like a woman, it doesn't change your gender. there isn't anything in game that can do that right now lol.
(also the only thing that relies on smell to find you from what I remember is the tar things near Viccoria.