I think it's silly to be jealous of someone who simply works hard, but it's the only thing I can think of. I plan on talking with my sensei about it, but I'd really appreciate any thoughts.
are you sure it's jealousy? what do you know about his life or anything about him other than his practice at the dojo? he could be bully or he could be not. sometimes, thoughts started out good in the head, by the time they reached the lips, things didn't sound the same. i remembered one time (ok, more than one) i was infatuated with a girl, the words came out of my lips just ended up completely wrong. so he doesn't practice as often, he could be working, school, and various other things that kept him from coming to practice. it could happen; thus my question, what do you know about him, of him?
read this story http://easternhealingarts.com/Articles/softanswer.html
in Sun Tzu's art of war, you must know yourself, and you must know others, before you can win. know either and you lose. knowing yourself, your true self, is the hardest, because you just met your worst enemy and your best of friend.