My standard is pretty strict. Many years ago, like 1960, I was at that dump of a beach, Colonial Beach Virginia. I saw , for the first time, a teen girl wearing a bikini. After a minute or two my father simply said.’You looked at the girl, she is pretty. Now look at something else, the river, the sand. That is what a gentleman does and it doesn’t matter what the girl does.’
Your dad was a wise man.
Also, you need to look at that picture. The woman had matts behind her. Look at where the man is. From where he was, he could see the back of her head, arms and back, but probably not much else of her body.