He's not actually gay
At least judging by search results I saw linking Cumberbatch romantically with several young hotties of the female persuasion. No doubt he's considered equal-opportunity eye-candy, judging by blog post titles like "Why the boys and girls are just wild about Benedict!", ad nauseum. I couldn't tell you why his character in "Tinker..." was gay, but in Sherlock, of course, they're riffing on a long tradition of speculation about Holmes and Watson, amid a gay-friendly society, on a network on a hot streak due largely to the militantly gay Russell T. Davies. If Doctor Who can get tongued by a guy, a little nudge-nudge-wink-wink on Sherlock is pretty mild.
Mainly, though, I wanted a subject line that would play off yours...;-)