A lot of guys who aren't attracted to men and are repulsed by the idea of intimate acts with men like kissing but who would enjoy some cock assume they're straight because of how attracted they are to women. They marry a woman and then turn 40 and have homosexual urges and worry about what it means because no one talks about the difference between being heterosexual and heteroromantic and how everyone assumes someone who is one of those is also the other.
Doing something because you're a submissive and you're ordered to seems like the opposite of something you wanted to do. If your wife orders you to suck cock and you get hard doing it, are you hard for the cock, hard because you have to suck it, hard because you're your wife's bitch and now another man knows it, hard because the guy whose cock you're sucking is mocking you or hard because sucking cock is fun to you? Or a combination? If guys who spent their entire lives inside their own heads with their own thoughts aren't sure, someone here isn't going to know better than you. Getting hard sucking a cock doesn't necessarily make you bi, and even if it does, what does bi even mean? Homoromantic and homosexual get lumped together but everyone is a balance of the two in a different ratio and who gives a shit?
I think the pronouncements of "this means this" in here are unproductive, inaccurate, oversimplified and ultimately unhelpful and damaging. Society as a whole is like this. If your wife likes it, fuck what everyone else thinks.