I love steamy scenes. A well written (and graphic) sex scene can move the story ahead as well as the black moment, the beginning hook, or even the moment they realize how they feel about each other. The level of graphic-ness in said scene describes the level of trust between your H/H more intimately than merely saying it ever could.
However, I've been debating the placement of such a scene in my latest story set in Germany. Too soon, and I feel as if they've jumped into bed for no real reason. Too late and I'm deep into the middle of the story and there's no real place for them to have sex.
I think that them having sex before marriage is valid since the time is 1934, and even in Germany mores about such things were in flux. Though I'd love to read anything anyone had on that, even if it contradicts my aforementioned hypothesis. That isn't the problem. The plot hits the ground running and doesn't stop. Having the couple intimate early on shows certain things I want to include - their level of trust and a fairly major taboo that's broken by the hero. Two actually, now that I think about it. (Well that 2nd depends on the direction of a tidbit I haven't decided on yet.)
But I still have that placement problem. Early on works on several levels. But would it turn a reader off? Would it skew the plot in a direction I don't want to go in? I don't want to write the scene, finish the story or even 1/3 of the story and then discover I need to seriously rework things. That's why I plot ahead. To avoid just this kind of headache.
I guess I'll write it, see how it gels, and hope my weekend isn't so booked I can't rework anything I don't like.