It's sometimes hard to make people understand that all we want is equality - which means that I can be the boss if I want and it doesn't mean I'm bossy, or be less visible if I decide it.
So at the beginning be nice, then talk loudly if the person doesn't want to understand (forgive my french), and finally if he still doesn't get it, it's not the right guy/girl/friend.
Also good luck if it's a member of your family