I'm fond of yaoi and especially of its subset, shota, but I'm not adverse to straight or yuri either. I've even subscribed to lolicon, although, and this applies to shota as well, there *is* limit for how young the character can be. If it's tastefully done, it's excusable, but even then I find it hard to justify going maybe ten.
On the whole, I'm willing to ignore the orientation if the story is well written, using the pairing as more of a guideline to what I feel into reading at that point in time. I think that having a preference for one over another is fine, but to the exclusion of all else might be a bit much. Never know when you might miss out on a diamond in a sea of glass, after all.