Bridges of Madison County

This movie compels me to write again about infidelity.
Robert Kincaid (Clint) noted something peculiar about modern society and each person's want for something(s). When Francesca remarked - 'Things Change',

Robert said, "They always do, it's one of the things of nature. Most people are afraid of change, but if you look at it as something you can always count on, then it can be a comfort. There are not many things you can count on."

This one stands out - "I don't think obsessions have a reason, that's why they're obsessions."

Francesca: You have friends too?
Robert: I'm a loner not a monk.
Francesca: You really don't need anyone?
Robert: No, I need everybody.

Francesca: You ever regret not having a family?
Robert: Not everyone's supposed to have a family.

What he noted about society:
"There's too much of 'This is mine' or 'He or she is mine'... Too many lines being drawn; that kinda thing... you know?"
Coming to infidelity. "She is mine!".
This statement ought not to make sense, but it does. We have been tuned to securing our surroundings and possessing things around us. Inanimate object should be fine but another person of free will?
What can stop a guy from pursuing sexual or emotional pleasures with another woman? In our society... Guilt, commitment and responsibility methinks.
People are fickle-minded and can sway from time to time. At times, we need to adjust to unacceptable behaviour.
When a guy has a random one night stand, not much is said... when a girl does the same, she is labeled a slut. Guys having one night stands are more common, but that is not possible... because usually, a guy would have a one night stand with a girl, implying that guys tend to brag about their adventures whereas girls are more secretive.
Secretive because of societal pressures and because a girl usually does not need to proclaim her accomplishments as much as a guy does. Hence, the age old debate about how women are more mature than men. Men succumb easily to ego boosts and proclamation of their achievements and turfs.