I'm thinking of breaking up with my ex because of instagram issues
What exactly is the problem with Instagram?
She's uploading her sexy photos and I am not comfortable with that.
You should talk to her gf about how she is making you uncomfortable for the sexy pictures. Hopefully she will listen and take those pix down.
Nope, not going to do that. I'm not going to be hers anymore so it doesn't matter what she does.
Ending a relationship is a big deal so you should think again before you end it for such a weird reason. Social media is used that way so she is not doing anything wrong.