My boyfriend's best friend just recently broke up with his girlfriend. I they've been going out since the beginning of the summer, but I had never met her until I started going to school with her. Now that we go to school we've become fairly good friends and were just beginning to reach the stage where we would hang out. She's a really nice girl and I plan to continue talking to her at school, but would it be harmful to my relationship with my boyfriend if I hung out with her outside of school as friends?