I was wondering if I'm bisexual because although I am attracted to women, and I'm in a steady relationship a girl, I find myself occasionally thinking about getting fucked by a guy when I jack off, but then as soon as I finish the thoughts dissapear. Does that make me bi or just curious?
The answer to the question would depend on whether that thought is sufficient enough to increase arousal in its own right. So, next time, when it catches you, just stop applying manual stimulation and focus entirely on that thought and...if you are able to continue expanding from that thought alone then you have your answer.