Gay and mixed race couples don't register with me. There was that Cheerios commercial a few years back with the mixed couple and I had to have someone explain to me what the hubbub was - I didn't really notice that they were of different races until it was specifically brought to my attention.
House of Cards is the only one of the shows mentioned that I've watched, and I saw the three-way with the security guy as more of a demonstration of just how creepy Underwood is (that was not just a three-way set up, it was seriously skeevy). That Frank and Claire have separate sex lives demonstrates that they are a political partnership, not a true loving marriage (as we saw clearly in later episodes).
By contrast, Mitch and Cam of Modern Family are one of the best TV couples in history and a good bit of their plotline revolves around them being gay. But they are freaking hilarious!! and I think even hetero couples can relate to them.
