It might be beneficial to divide this trope into two subcategories: one for characters who are heterosexual but just insistent, and one for characters who are actually homosexual but denying it.

If the consensus is that that's a beneficial change to make, I don't know how much use I'd be in getting started, seeing as there's so many examples already listed of characters I don't know at all where the description also doesn't make it clear into which heading they'd belong. But I'd be with you in spirit.