dealing with your child's fathers girlfriend???

I've had this issue with this young lady since me and my child's father were dating. She always post subliminal things in regards to me or regards to our relationship. I never addressed it. I ended up getting pregnant and me and him split. During my pregnancy, the got back together. I didn't hear anything from her till I was in my last trimester and I agreed to "make mends". Well a little less than a month after my son was born, the subliminal post and comments started AGAIN. I mentioned it to my child's father and he swore he talked to her about it but I'm guessing he didn't because they continued. The broke up a few months later and the post stopped but she began talking sumbliminally about another girl he was talking to. NOW, my son is 10 months old and it has started AGAIN! I'm pretty much at the point of just taking it into my own hands and I don't mean in a pretty way lol. I feel like I have been the bigger person about this but this has been going on since early 2015. At this point I don't know a genuine way to handle it.. and I am trying my hardest not to mention it to my holds father because my brother killed himself a few years ago dealing with the stress of his girlfriend constantly fighting with his kids mother..What better way could I handle the situation without losing my last peace of mind I have left??