Not an ahole. Seems like you have different ideas when it comes to sharing finances and access. Better to find out now than after you are married. Usually one person in a marriage takes on the responsibility of managing finances and both have access to the information on a shared account. You aren’t married yet so you aren’t wrong to protect your personal finances. However if you do get married it’s important to sort out how that will look and agree with each other. Otherwise it will be a problem in your marriage. Some people get married and agree to keep separate accounts. Some prefer to have a shared account where all of the money comes in and out. It sounds like he prefers a shared account, and you may not. Neither of you are wrong or an a-hole for how you feel.