Dealing with ex-wife of my partner?

I am in a relationship with a man I was involved with over 20 years ago. We have re-connected again and are happy most of the time. He is going through a messy divorce and property settlement. He has joint custody of his 15 year old daughter. We have been dating for eight months and in this time, I have had to endure her endless abusive phone calls and text messages to him. He wants to "keep the peace" according to him so he endures this verbal abuse. She is an alcoholic and when she is on a binge the taunts start. I have been supportive of him and listened to his woes and he does not always bring her up in conversation but lately I am starting to tire of it. Somestimes he even defends her saying "she was a good wife for 16 years till she started drinking heavily" . Well, this is all well and good but she is not a nice person now so I say "no excuses" for her poor behaviour. I want to be supportive of him and help him through the bad times but I am feeling hemmed in and feel this situation is going to go on for a long time as the court battle has not yet begun. How would others suggest I handle this situation?