It's Hard To Turn An A**hole Into Not An A**hole

This woman is dealing with her sister's boyfriend who has embedded misogyny, is disrespectful to your parents while living under their roof and also won't drop stupid arguments such as whether or not your bladder muscles are strengthened or weakened by holding in your pee. She wants to know if she can change him for the better. My mom and weigh in if this is even plausible. Also, can you strengthen or weaken your bladder muscles by holding in your pee?