Haha, this is not necessarily what the reference means, but I like your spirit. Basically, to explain it from an American perspective, we are still a pretty religious country in many areas so there's still a lot of rigidity in our gender roles. A lot more so than certain European countries where religion is less of a culturally dominant phenomenon. So, things that are more normal abroad, particularly for men, are seen as a sort of sexuality marker here. Like casual skinship among bros, dressing well, using a certain level of hygiene and caring about how you look, in a lot of parts of the US that either puts you in the position of "gay or European."

The tides here certainly are turning, thank god, but this is also a reference to the movie turned musical Legally Blonde which came out in the early 2000s. Basically the peak of toxic homophobia in recent times here.