Interesting question, really interesting. It depends on many factors such as what exactly we mean by a long romantic relationship. In fact we have some of those things, but I don't think we focused on revealing them the basis is of course debauchery, as you might have guessed. But our characters live in the same environment and relationships develop between them.
So I can't give you a definite answer, you'll have to give the game a chance and see if it has what you're looking for.