I remember suspecting a First Officer's girlfriend/wife in the cockpit on a CMB-BKK-HKG flight. (Now, keep your mind in the straight and narrow please! )

Reason for my suspicion is that I remember seeing quite a cute girl by herself at the departure gate. Then as I was one of the first to board, I didn't recall seeing her walking past me (I was in J on a 773).

Anyway, the next time I saw her was at the BKK stop, holding the First Officer's hand coming from the cockpit/gallery, i.e., from the front of the plane. From BKK-HKG, she was by herself in the last row of J.