Of course, this is a common source of Unfortunate Implications. So basically, you can have same-sex couples, but they can't be shown actually behaving like a couple. If one of the characters is bisexual, don't be surprised if their opposite-sex encounters are as steamy as the rating allows, but suddenly they become as temperate as a monk when they're with a partner of the same sex. There may be a hug, or a meaningful handhold, but never a kiss unless it's heavily promoted and advertised (and even then, don't get your hopes up that it will happen as advertised).
So television shows and other media don't push the envelope too much on gay affection. Homosexuality is still a taboo in much of the world, and while some audiences may tolerate a gay character, they may be completely squicked out by shows of affection and sex scenes with gay and lesbian characters, no matter how tame they may be. However, there is a bit of a Double Standard regarding same-gender love portrayals and love scenes and the like. You want to feature a queer character on your show or, hell, make them the starring character! But what if they get a Love Interest? Will they flirt? Kiss? Hold hands? Have anything resembling or implying a sex life? Gay characters enjoy increased visibility in media and numerous positive portrayals. Okay, let's say you're done hiding your lesbians and you don't want to bury any gays.
