If you are primarily focused on maximizing the chances of starting a relationship with a specific girl, it may be best not to bring up your stuttering unless she asks about it. On the other hand, if you feel insecure about your stuttering and are worried that a bad date could lead to depression, it might be better to mention it beforehand so that you can feel more confident and comfortable. In my experience, it's usually better not to bring up the fact that you stutter unless the other person asks about it. This is because some girls might not want to go on a date with you if you mention it upfront, while others might actually feel more comfortable on the date if you tell them about it beforehand. Ultimately, it's up to you to decide how and when to bring up the topic of your stuttering, but these are some things to consider.