I think you helped me crack it, i think it’s saying that the person who looks like you but puts in more effort to their appearance on the regular is more attractive. That makes sense to me, and would be true in the main for most people, it’s one of the most common things said to people who are struggling to find partners.
You could take negative connotations from that about that person being vain but really it should be on the cheater for being a fucking cheater.
Watching UK 70s TV now is wild. Prime time sitcoms using camp gay sterotypes as a punchline in themselves, black characters being called Chalkie or similar. These had regular repeats throughout the 80s on the main TV channels. Hell, known ephebophilie and bigot, Jim Davidson, had a prime time game show till 2002 and would regularly do his Chalkie character on it.
Late 90s/early 2000s UK TV was still pretty homophobic and racist, see Little Britain for yellow and brown face combined with racial stereotypes, big name comedians of the time like Frank Skinner making homophobic jokes.
Early 2000s in the UK was aggressively misogynistic, mostly in the printed press, absolutely rabid.
Obviously these issues haven’t been solved, but at least its unacceptable for mainstream TV in the UK to pedal this shit.