The same is true of creating and running RPG scenarios for your friend. In both cases, bear in mind the fundamental difference between writing a story and playing the game. When you write a story, everything in it comes through you. You don't always feel in control, but you are. When you play a role-playing game, either as DM or player, you are collaborating with your friends, and the game isn't successful if everyone doesn't have a good time.
Writers are high-maintenance partners.
We can be deadly to those we marry, and those we marry can be deadly to us. Charlotte Bront ceased writing when she married. George Eliot didn't hit her groove till she settled down with George Henry Lewes. Lord Byron, Samuel Taylor Coleridge, and W.B. Yeats would make everyone's list of lousy husbands, but Elizabeth Barrett and Robert Browning made a classic team. I can't tell you who to marry, but I can tell you what to look for.