In our case it is not all that difficult. Even when we are out together, my wife will sometimes strike up a conversation with a stranger, without including me at all. She is very outgoing and loves to flirt if you pick up on her little hints. And whenever she starts a conversation with a single guy, you can count on her having sex in the back of her mind.
Just from looks you would never be able to tell. Here is a pic of us from a few years ago.
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