Many men will wolf-whistle at any woman.*
So it’s not a special insult toward the woman in question (yes, men, wolf-whistles are insulting when they occur in everyday contexts—because they emphasize our sexuality when we’re trying to be seen for our personhood and our various competencies; it thus reduces us to sexual objects) (a wolf-whistle in the bedroom directed toward your consenting sexual partner is, can be, a completely different matter).
Instead, such blanket expressions are indications of the man’s insecurity about his manhood: he feels the need to assure himself and/or others, since his behaviour is public, that he’s a man. Apparently, to such men, finding women sexually attractive is proof of manhood. Heterosexual manhood. So really the wolf-whistle is an indication of homophobia.
So rather than focus on the inherent misogyny, we should focus on his insecurity. And, therefore, we should respond with something like “Don’t use me to deal with your insecurity about ‘being a man’!”
Granted, most men won’t understand that, so you’ll have to simplify and expand with something like “I understand that you’re afraid that your friends think you’re gay, but don’t use me to deal with that fear. Just talk to your friends; tell them you’re not gay.”
(Right. Like that’s ever gonna happen.)
And those who are smart enough to understand our initial response will be so resistant they won’t process it. Because introspection, self-awareness—these are not part of the definition of manhood. (My father hated it whenever I tried to get him to examine his behaviour – ‘Are you trying to psychoanalyze me?’ he’d shout. As if I was proposing castration.) (I suspect that like most men, he was afraid I’d discover there’s nothing much there; men spend so much time thinking about strategy, at heart, a sort of duplicitous insincerity, they haven’t developed any genuine core.)
*And once women realize that, perhaps they’ll give up the make-up, the dress, the body obsession: to men, it really doesn’t matter how you look.