Secret bank account

I want a secret bank account/savings account. How do I go about that? I’m just nervous mail is going to be sent and he’ll find it. Or find out another way that I don’t know. I only plan on having $20 of my paycheck going in the account each paycheck.

Edit: we both have the banking app so if I open up a savings, will he see it on the app? Do I have to open a savings with another bank? I guess I’m confused. Also, I’m doing this because he always nags about my spending. He’s cheap, always has been. I don’t go shopping for myself ever. It’s food. I eat healthy and I love everything. He, on the other hand, eats shit. He’ll even complain that my burrito from Taco Bell is $4! He drinks bud light and just because I like craft beers and VARIETY, he complains that I drink the most expensive beer. I bought mine and my sisters breakfast yesterday because I owed her and he freaks out like, “you spent $33 on breakfast?!” Those are just examples. It’s stressful. I shouldn’t have to feel afraid to buy things for myself. We don’t have a lot of money but our bills are always paid on time.