LGBTQ characters as non-issue
So, I've been toying around with having my protagonist in the project I'm working on be bisexual for a while. If I did, it would be completely a non-issue. My work is along the lines of John Green/Eireann Corrigan (romantic, funny, but serious too), and there are many other things that the book is going to address. After reading what people are looking for, I feel like it might be good to do this with my character. But, my hesitation is I'm wondering if we can even have non-straight characters as a non-issue. Would it be distracting and take away from the other things I'm trying to go into with this book? Would people expect/be disappointed if I didn't address it as an issue? Also, since my writing is male POV, and would likely be geared toward boys, would a bisexual male protagonist be a turn off? In all likelihood, this would be the second book of my career, and I'm wondering if I should step out on this limb or whether it could potentially be career suicide. I plan on asking my agent when the time comes, but I wanted to get the board's opinion.
So, what do you all think? Can non-straight characters be treated as a non-issue without being a distraction (to a mainstream audience, that is)?