Guy's Behavior

Why are some guys so desperate and jealous?

I was at the gym yesterday and this hot girl decided to choose the treadmill next to me out of all the empty ones. Im currently talking to another girl so i just ignored her. Well this guy on a treadmill infront of me kept turning around to look at this girl he seemed desperate he also looked at me because i think he might have gotten jealous. Why are some guys desperate and jealous like this?
Why are some guys so desperate and jealous?
Post Opinion