Very annoyed... my fiancé and I can’t agree on finding out the gender

Any tips to sort this out? I do not want to find out and he does... I feel like if he finds out he is going to be soo disappointed when he sees it’s a girl. I’ve expressed that I would rather wait til birth so we can celebrate together on the gender and be there for each other (he realllly wants a boy) but He just will not budge. Exercising his ‘rights’ as the father which I can understand but I just hate that he thinks he can find out and keep it to himself and not tell me or a single soul. He’s the kinda guy that accidentally blurts shit he shouldn’t out to people. Or he’ll say ‘him’ or ‘her’ accidentally unfortunately he can’t be trusted with such exciting information!!! How can we get past this???