It is possible for an H1B visa holder to work part-time for two different employers, but there are specific requirements and procedures to follow. But it's definitely possible

Nope, you have to reapply my broer

as far as the H-1B rules are concerned, you can work concurrently full- or part-time for one, two, or several U.S. employers, so long as each job qualifies as an H-1B occupation and each employer is willing to take on the H-1B obligations.