Despite her principles or history of integrity, is a woman’s faithfulness dependent on proximity? Does it rely on the magnitude, the temptation, of the situation?

What about circumstances involving very tempting factors? A very attractive guy courting her with the right sexual advances, at the right time

I’m just curious if a woman’s fidelity can be reasonably expected to be steadfast in any or most situations

Ex: Would you allow your wife to take daily “swimming lessons” alone from a put-together, male who is obviously a dude that women would find attractive? Could you really be so sure of her fidelity to you? (I’m 20yrs, definitely not in this situation at all, just hypothetical)

My grand question:

Is it insecure or is it reasonable for a man to forbid his wife from closely associating with another dude?

My church member & his wife really made me consider this. Whenever his wife comes around she always starts long conversations with me while her, seemingly meek, husband stands back and watches. He can’t enjoy it (unless cuck), just maybe he isn’t bothered by it. She is a very short petite woman compared to me, tall dark & handsome and she makes pretty strong eye contact while talking (which sometimes makes me uncomfortable since I’m associates with her husband, as I try not to send any ambiguous signals). But if he’s really unbothered, I’m surprised at his trust in her. She compliments my looks a lot, she obviously recognizes my attractiveness, it isn’t a sin or offense, but I was wondering if, while we where alone, I tried to advance with her, or made some type of lewd joke or flirtation, would she be receptive in any way, or will she immediately shut it down (which I very much hope she would, just for my hope in humanity) (I don’t have the disrespect in me to attempt something like that most definitely though)