Slappin' women's asses was about as innocuous as giving your bro a high-five (pre-corona). The last vestige of this type of social behavior (probably because they're the only *manly* men left in society) is construction workers catcalling sexy women as they walk by. Women used to almost see it as a badge of honor: if they got whistled at or hit-on walking by a construction site, it was affirmation of their desirability as a woman— and she'd probably brag about it to her friends, later. It was a very different time; almost literally an entirely different country. Back when you could smoke in restaurants and hang faggots from trees, without getting hassled by anyone.