I once (2003 or so) had booked a MR DTW-LAS-MSP-DTW where one of the female FAs was with me for the whole routing (IIRC on the last leg as a pax). She approached me in MSP and asked me if I'm following her. She sounded like she thought of reporting me to the authorities as what I did certainly was not explainable to her... I told her about the concept of a MR and she never heard about that before. I'm not sure she believed me...