That is exactly the couples I like to play, but I have couples of all types. They are like sour candies <3
Oh the Sims 3 nostalgia: Moonlight Falls (Supernatural EP) was my fav world of that series... there I played a supernatural couple, a vamp and a fairy. They were opposites. But they story was the saddest ever :'( Do you remember that Philosopher's Stone thing? My fairy died because of it and was turned into a gold statue.
At the front yard of my vamp house the golden statue surrounded by flowers was the reminder of his broken heart.
Meh I do not want a sad ending for Tsuki and Isidore :s