My SO & the girl who cuts his hair

Miranda • pregnant with our first !
Am I wrong? Prior to our marriage, I'd caught my husband conversing with other women & put an end to it. I don't mind my husband having friends that are women as long as they are OUR friends. However, the women that cuts his hair just rubs me the wrong way. She'll text him about stuff that has nothing to do with him going to get a hair cut. The most recent that I've seen was "I didn't know you were married". (We've been married only 6 months but have been together 7 years) I REALLY don't know how to approach the situation ! How do I express to him that I don't want her cutting his hair anymore?! I feel like if it were a professional relationship from the beginning there's no need to converse about the fact that he is married! Am I insecure ? I don't think so because she isn't very pleasant looking. I love my husband to death & want nothing but happiness in our marriage, we don't argue. It's very seldom that we even have a slight disagreement & it's been this way for 7 years. My fear is approaching this the wrong way & causing an argument ! Any advice ?