Joe

Joe is a sewer monster. You meet him at the end of sewer level 1, after which you will be able to spend the night at his place, such as it is. Do that a handful of times and you will be opening up Joe as a romantic partner (i.e. you can take him on dates like the other NPCs).
Dating Joe
He likes you to dress as conservatively as possible (dress, bra), wear the light perfume, and take him to a quiet place where he won't be seen (pub).
He enjoys soda and meat meat meat. Also brownies.
For an after dinner activity, take him somewhere dark where he can be himself (XXX theatre).
Doing all this will make the date end suck-sessfully.
Purple coin ending line:I may not talk much...But I can lend you strength...