I couldn't vote in your poll because my choice wasn't there. Basically, I don't think it is up to you and your Primary to dictate to your Secondary what kind of conversations he should be having with his other girlfriend. You manage your relationships and let him manage his. There seems to be a whole lot of control issues going on here.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein