It’s a fictional vignette with a contrived twist. You should argue that the boyfriend reveal doesn’t make sense.

The original sentiment this is a variation on is showing up for a stranger who seems uncomfortable or feeling harassed in an unwanted social interaction by giving them an invented out. That’s what most people are assuming the context is.

You make the point that not all men who hit on women at the gym are rapists/creeps, they just need to learn social norms. Well, this is a social norm: going up to a stranger with no context/prior conversation and saying “Your body part is appealing to me, want to go out?” Is not socially okay because it’s perceived as leery and objectifying, like you’re shopping for a car, not trying to form a connection.

Here’s another social norm: Chat people up at the gym and see if they’re even open to having a normal fucking conversation with you like you’re both human beings. Learn something about them if they are. Then go from there.

TL;DR: Hit on people in a humanizing way, not in a creepy way.

Is it sleazy? Absolutely. Is it exploitation of a massive power imbalance? Undoubtedly. Is it illegal? Probably about as illegal as a game pre-loading 4gb of DLC I’m not going to buy as part of an automatic update. The terms of your agreement with Google for Chrome allow them to update their software as they see fit. Their gamble is that you won’t switch.