Why is that when I see a handsome guy, I wanna jump him?

Boys/men love the chase, by instinct. You've created a challenge for him, which has egged him on to conquer. lol
Usually once they get what they want, they get easily bored and move right on to the next. Like I said...they love the chase...they're mostly all the same. Keep your head. If you like him too, then date him, but there's no rush. The worse thing you could do is get enthralled with lust. Many mistake lust as being love. Boys don't think like girls do. Sex to them, does NOT mean they're in love with you! Not in the least. It's just sex.

At that age, they're more out for lust and will tell you they love you, just to get sex. Be smarter than to fall for that. Have respect for yourself and they will too. The minute you give in, they'll be gone, guaranteed, and so will your reputation. You're much too young to tie yourself down and have babies.

Yeah. That's called being a hormonal teenager.

either date him or don't. don't lead him on. or don't get upset if he finds someone else while your too busy playing games.

Just say yes to him...