There comes a time where you need to talk about finances with your significant other. It may seem like a hard subject to talk to each other about but it needs to happen so the first step is to admit that the conversation needs to happen. Be prepared but relaxed and talk to each other about your financial goals and if you want to combine bank accounts or not. Most important thing is to be honest with each other.
Below is a video that offers some advice for when the time comes.