As a combat oriented role-playing game, Dungeons and Dragons 4th edition holds a tension between the tactical parts of the game and the character elements. I’m a fan of both, so I constantly try to inject flourishes into my player characters.
One often overlooked and avoided way to inject true character into your PC is to reflect on and identify a sexual orientation. Many gamers avoid anything to do with sex in their game: for some of us, our early gaming experiences were as teenagers when we knew little about human sexuality; when the topic came up, it likely to descend into adolescent silliness. There is also the concern of the gaming group becoming creepy or feeling threatening to those uncomfortable including sex in the game.
These concerns are fair. While it is reasonable for a group of adult gamers to focus on romance and other aspects of human relationships, most D&D groups frankly aren’t interested. As an aside, the Book of Erotic Fantasy by Gwendolyn Kestrel and Duncan Scott is a supplement that is compatible for the 3.5 rule system that focuses exactly on “intrigue and manipulation, marriages of power, dangerous seducers, sex and magic.”
Even for standard hack and slash Dungeons and Dragons campaigns, simply identifying your character’s sexual orientation is a large step toward making him seem more real. It is then interesting to flesh out a character’s interest in relationships. Consider Westley’s situation before the action really started in The Princess Bride. He is clearly straight, but when he was away, becoming The Dread Pirate Roberts, he had no interest in pursuing other relationships. Spielberg’s Indiana Jones, Wildstorm comics’ Midnighter (member of Authority) and Moorcocks’ Elric of Melnibone are other characters with established sexual orientations that added something to their personas.
If your group isn’t in to it, there’s no need to role-play any of the details. This doesn’t mean you can’t add story elements to the back story or into the out-of-play scenes.