my younger doggy acts out when his older doggy brother is home πŸ˜£πŸ˜£πŸ€”πŸ€”

i have two dogs lately my younger dog had been acting super hyper active i know it's not out of the ordinary hes only 10 months BUTTT this weekend my big boy went on a mini vacation with grandma and my youngest doggy did AMAZING i was SHOCKED πŸ˜‘πŸ˜‘πŸ˜‘ his listen was amazing, no bitting, no accidents in the house, no broking things... fyi my older dog doesn't do these things so I know it isn't a monkey see monkey do so I don't it, wht one going through a similar situation or understand what might be going through his head