Darling wa Namamono ni Tsuki

From MangaProject: Imagine what it is like to be raised by a gay father who insists that you call him "mom". The main character turns out to be a woman who doubts her sexual orientation, until she meets the right guy. She is so sure that he is "the one," that she goes out of her way to pursue him and then marries him lightning fast! Essentially, the rest of the story is about keeping the chemistry (a little twisted and crazy though).