I think she doesnt "see" his husband cause:
A) it's all dim and the mask won't let her see well
B) she is too busy feeling and moving to put attention
C) her husband was very different in bed to this giggolo, the idea of them being the same person could never be an option, they probably had pretty stale sex: fully clothed, barely any foreplay, just doing the deed for a few minutes without any emotion... Sex CAN be very boring and nothing like fairytales, in marrige both parties have to step it up and be into it
ヾ(☆▽☆)