Am I unreasonable/stingy for doing this?

Okay ladies, so I just now stared working. $10 an hour, part time, 30 hours a week. I just opened my own bank account because I want to start saving up money for a lot of things. Wedding which is 4 months away, car, house, and all the fun good adult stuff. Yay. Well my fiancé got pissy at me for not sharing bank account with him. I won't because HE CANNIT MANAGE MONEY!! He used to make $1,100 every 2 weeks and he has not saved a penny. He has $10 left in his checking and like $32 in his savings. On his very last paycheck he spent $500 for a Ps4 that he doesn't even get on anymore. We had to make the money last to get buy and pay our phone bill and stuff now his mom is having to do it which she shouldn't at all!!!! I and to get a job because if it. Is it wrong for me to be this way?? I dont trust him with money whatsoever. He blows it.