And then problem number two, and perhaps the larger issue, is the question of which naked bodies to put on the cover. Because again, overwhelmingly, the bodies are almost always female. Or you might get a heterosexual couple. And maybe you want to counter that trend because a) you are very tired of it, and b) why must women's bodies always always always be the ones we stare at, and c) the book is pansexual and has at least one or two queer stories in it, along with the straighter ones.
But if you just put a male body on the cover, I think it reads as romance to the casual book cover viewer? And if you put a gay couple on the cover, then readers will likely expect it is an exclusively gay book, which again, is going to mislead readers, which I wouldn't care about so much except that a) a bunch of straight readers will not pick it up because they assume it's not for them, and b) a bunch of gay readers will pick it up and then be annoyed that the content is mostly straight.
And the problem might be solved by adding more bodies, but then a) readers might expect a lot of orgies in the book, and be sad when there aren't any, in fact, and b) it will likely start making for a very cluttered cover, which is aesthetically troubling, and c) it will leave no room for your name and the title, which kind of defeats the entire purpose of the book cover. Especially when the cover is seen as a tiny thumbnail image in an online bookstore.
I could go the 50 Shades route and just put an iconic item on the cover, like the handcuffs, etc., which is at least visually clean, but a) I'm tired of that trend too, and b) it's not an S&M book, and I don't know what would be an iconic image for a book about, y'know, people. In relationships, or not. Talking to each other, or not. And having sex.