This happens to me relatively often. I get chided by the family for it quite often, though thankfully they're past the 'OMGWTF' stage and they've entered into the passingly amused stage, took them long enough though one must say. It manifests itself with me in all manner of ways. I believe the most recent was an instance of ...
",,,pssst, you're yawning like the Dog again, stop that..."
"Rrr..nngg...Ruuf? Beg pardon?"
"Oh bloody 'ell. People 'ill stare, yanno."