If you are a “sounding board” you could try being a bad one. Instead of offering sympathy or criticism, try just not reacting at all.

Just say oh. Not yes, not no, just a non-reaction.

My boyfriend is an asshole, That must be awful It is… let me tell you all about it.

My boyfriend is an asshole Maybe you should leave him But I love him…let me tell you why

My boyfriend is an asshole Oh He did this to me Oh I love him Oh What should I do? I don’t have anything to say