So if my dad is not ignoring calls from him (& I know he is not), then how could my dad be "not talking to him"?
Well, it occurs to me that maybe my parents have been in the habit of calling Bro2 to catch up & chat, & perhaps my dad is no longer doing that.
Here's the thing: my parents don't call any of the rest of us. WE call THEM when WE want to talk. That's been true at least since I went to college. They will always pick up, they'll talk as long as you want, but it's entirely on our terms.