Open to who I play but I'd like to play a male celebrity (or photographer) that finds out a big secret about a female celebrity: That she has a cock. This could turn in to a blackmail situation or something where they explore some together since she can finally be open about her secret or anything along those lines.
He would likely want her to be a bottom /most/ of the time. But again, exploration is a key part of how things can go depending on the pairing/relationship!