As for turn on or embarrass I guess it depends on her reaction...
If she walked in and was immediately "WTF" guess maybe it would be embarrassing.
But if it was a case of I saw her and realized she had been watching then turn on.
I think my wife's first reaction would be "why didn't you wake me up" then "Well, hey, now that I'm here why waste it?"
She travels for work here and there and when she does we get off in front of each other on skype so she does like to watch, but if she is in the house that load better be coming her way...
"There is an expression; all men are created equal. This statement is a lie, no doubt created to help those who wallow in mediocrity feel better about themselves." The Lady Persephone, Grand Mistress of the Circle.