Am I being way too jelous with my bf?

[735]

Theres this girl that likes all of my bf's pics and she is just so annoying I can tell she thinks he is hot. I know this because she likes all of his pics on instagram, and then one time his brother put a picture of both of them and she commented with that smiley face with two hearts in the eyes on the picture. And she could be referring to his brother but Im sure it is both.

Him and her do not talk but one time I added her just to see who she is and she accepted and added me and then ended up blocking me!!! this really pissed me off in that she knows I am dating him and then she blocks me and continues to like my bfs pic..I wanna just slap her because I know how girls are.

Now my bf thinks its silly to block her or delete her because she hasnt directly done anything to him or commented on his picture, and that she commented that on his bros pic. She just makes me uncomfortabl esp since she blocked me. Also when a guy hits on me or mssges me and comments somethin on my pic, I delete them if my bf is uncomf yet he is saying that this girl hasnt done anything.

Do you think I am overreacting? should I only be upset if she comments on his own pics and says somethin to him? or do I have a right to be upset.