Actually, there are very, very few shows and movies in which it is either explicitly stated or implied that a character is only heterosexual, if they're depicted in a heterosexual relationship. Considering the statistical presence of gay and bisexual people in the real general population, if you took all the fictional characters there are, subtract the percentage of ones presented as canon gay or bi, there are still a lot more NOT accounted for of what's left.

Go revel in your canon. Oh, and don't tell people downthread that you don't care what they write, because you clearly do, or you wouldn't have offered up your opinion, unsolicited, on this secret. :-)