Re: Hmm ...
Have you never heard of a "Dear John" letter?
So your argument here, is that sometimes women will dump men, so it's find to sleep with a model at a trade show?
The "toxic masculinity" thing is toxic because society in general looks down on women who cheat on their partners, but not on men who do the same. A guy who sleeps around is "Jack the lad", but if a woman does that, she will be shamed. And of course, women cheat on men, just as men cheat on women (and women cheat on women, men on men, etc. etc.) Just because someone else might do it, doesn't justify doing it yourself. "Don't be an arsehole" isn't a bad motto to live by.
Are you going to honestly tell me that you have never, when dating someone, run across somebody that suits your needs/wants more precisely?
Two things here - if you don't like the person you are with, you shouldn't stick around until you "find something better". String someone along isn't exactly a good character trait. Of course, if you do get on with the person you are with, you shouldn't cheat on them, just because you happen to run across someone you fancy more.
Of course, sometimes it happens that you may be in a relationship that is plodding along, and you run across someone who is obviously going to make you much happier. You don't just jump into bed with them and betray your partner though, unless you are a proper arsehole. I really don't think that a model at a trade show who slips you her hotel room number is going to fall into this category. You'd be naïve to think that such a liaison would be anything other than a one-night stand. Of course, there's nothing wrong with that sort of thing between consenting adults, if you don't already have a committed partner.
The only toxicity here is you assuming that everybody else on the planet must obey your moral understanding of the world. Who died and placed you in charge of our morals?
I never claimed to be "in charge of anyone's morals", but if you're going to act like an arsehole, be prepared to be called out on it. Your moral compass seems to be firmly set towards the "self gratification and screw everyone else" setting, so I'd suggest that maybe you should think about the effects your actions have on others. It's a fairly basic concept, and not "holier-than-thou" moralising to suggest that you don't go around doing whatever you want without any regard for the effects on others. You don't have to look very far in the world to see the results of people acting entirely selfishly. You might do well out of it; you might even get to run a country, but you sure as hell are going to cause a lot of damage along the way with an attitude like that.