So, if someone is mamón, they’re snobby, stuck-up, up their own arse, etc., etc. Yeah, you DON’T want to be called mamón… it ain’t a good look. Fun fact: I have actually been called a mamón in Mexico TO MY FACE. We were buying dog food in Tlaxcala and I was telling the guy that my dogs always eat the same branded food. And I think maybe he thought I wouldn’t understand, but as he walked past me later he muttered “pinche mamón” under his breath. Of course, I understood every word, lol. People in Tlaxcala are generally VERY, VERY polite and friendly, by the way. This dude was a complete anomaly. And to be fair, I probably was being a bit mamón… but I do also like to look after my doggies, lol. Anyway, ¡No seas mamón! has a slightly different meaning. Imagine something annoying, inconvenient, unfair, or just incredibly fucking frustrating happens. Well, you could say to yourself: ¡No seas mamón! So yeah, it means something like: 👉 Come the fuck on! / For fuck's sake! / You’ve got to be fucking joking! And when said to a person, it’s more like: ➡️ Don’t be a dick! / Don’t be ridiculous!