Flirty girl won't stop

So my SO has this friend thats a girl. I am totally cool with him having friends of the opposite sex. I trust him fully. The issue with this specific girl though is she is a huge flirt. She flirts with him constantly. She feels the need to love his statuses... Every single one! She also likes to post heart eyes on his pics and kissy faces. She's called him cute. She sits here acting like my friend then goes behind my back and hits on my man. He has always shut her down and or ignored her flirty comments. He has even told her that we are both uncomfortable with it. But then just dropped it cause he didn't want her feeling weird or upset. It worked for a bit, but then it started up again. I pulled her aside and told her how it made me feel. I told her I understand they are friends and I don't want their friendship ruined at all. I discussed with her that id like for us all to get along, but I told her to tone it down. I told her to find her own, because mine is taken. She was sweet and understanding. She stopped being flirty for 2 weeks maybe. Then my bf and I had a huge fight. We didn't break up. We are still together and working on us. But as soon as she saw we were in a rough patch the flirting started again stronger than ever. They have been friends a long time and didn't start flirting with him till she got a divorced. I really wanted to be friends with this girl for my boyfriends sake, but everytime I hear her name I get sick. I want to punch her in her wore face. Am I in the wrong?