When I bench press, the bar moves and it makes my arm move, I

Its called benching the weight. You have to move your arms and the bar in order to do the exercise

>>39539763
Lol

>>39539763
The bar doesn't move up and down, it moves to the sides and makes me lose the balance :(

>>39539802
Either use even heavier weight or train your arms the same. Jerk off too much? It sounds like one arm is stronger than the other and you're not controlling them enough to move at the same pace. Heavier weight will equal this out somewhat, or just focus on how fast you push the bar up.

>>39539751

bet you're not stable on the bench or w/e

fix your form