Actually, 90% man has this syndrome, if they have no erection problems. Most of them never realize or acknowledge this. So, don't laugh at this guy. Admire him because he can sense and detect the sexy girl nearby even in sleep.
When it is huge, it usually is faked, just like those in AV. Anyway, showing the faked one behind a faked couple is nothing wrong. But we do not know whether these two are real couples, or casual mates.