If you're a truly submissive man, a desire to suck cock for a Dominant woman doesn't make you bisexual. In fact, in my opinion, actually enjoying forced bi activities doesn't even make you bisexual.
What male subs have to ask themselves is this, "Do I desire to be sexually intimate with another man without being forced or encouraged by a Dominant woman?"
If your answer is no, I would not consider you bisexual.
Read my other blogs about forced bi.