Hypothetical Scenario: Let's say you were going to the beach with your girlfriend. You park your car, get your stuff and just as you and her are about to walk away from your car.......A guy pulls up in a drop-top Ferrari GT and swerves into the parking spot right next to you. He gets out of the car and not only is he taller than you, he's better looking too. His shirt is off and his six pack is crazy, he pretty much looks like a Calvin Klein model.
On top of this, his girlfriend looks like a Victoria's Secret supermodel and makes your girlfriend look like a butterface. Not to mention she has bigger boobs too. To add insult to injury your girlfriend is clearly checking him out, as much as she's trying not to make it obvious to you. You glance into his car and notice a Harvard/Yale/Cambridge/Other amazing university student I.D., proving he's intelligent. Lastly the guy smiles and says hello to you politely as he passes by, proving he also isn't a douchebag.
In the face of a clearly superior Alpha-Male that is essentially better than you in every way. Would you be jealous?