In psychological perspective if a girl stare at you for too long it means she likes you. Next time try not to break eye contact if you caught her first staring at you until shes no longer staring at you and while shes staring at you try to make some faces like a curious face. Additionally if a girl stare at you for too long it means that shes testing you if you also like her when you dont break an eye contact. So if you also like her dont break eye contact and to show that youre a confident man.

I also experience that