It's the direct announcement that gets me. If it is no big deal, they just say what is on your mind. Course, I use this sometimes if I'm asking someone a personal question or one that could overstep our boundaries. "Can I ask you something?" or "Can I ask you a question?" The answer is generally yes, duh. No need to announce it. To me, I think I assume that the other person knows that asking if I can ask a question means I am going to get serious or potentially awkward. It's indicating a shift in tone.

Hmm.