"I don't know if it looks vulnerable or just weak and stupid, honestly." Exactly, you don't know. You don't know the listener's experience so don't make assumptions. You can stutter easy or hard. Try to make it an enjoyable experience while stuttering. She's just a girl. Make her feel comfortable. Try to get her talking about topics she enjoys. You can comment on your speech and joke about it. I'll say things like "anyone else hate rs?" or "those damn Ts, everytime!" (with a smile, of course.) Set the frame. It's only stuttering; you're not the first or the last to have it. Don't try to control your speech. Maintain eye contact, eye contact is key. Don't be needy or pushy. Boost her. Good luck.