Can I get an injunction to stop phone calls from my sister to my ex-husband?

Sister who lives in Pennsylvania calls her ex-brother-in-law (an attorney in Dallas, TX). As his ex-wife, I think these calls are inappropriate. She will not stop calling him on a regular basis after being asked. He will not cease and desist keeping up the dialog because I believe he is conducting some sort of informal "interrogatories" to get financial information of my family that is clearly none of his business. I would not class the calls as "harassing", just annoying. Since they will not stop talking to each other voluntarily, do I have a legal remedy In Texas to formally have them cease and desist the dialog?