I was thinking (I do that sometimes) maybe you could run it by your H first and ask him if this MC offers separate sessions how he would feel about each of you meeting with MC both together and alone.
That would at least show your H you are considering how he would feel about meeting with the MC alone and show him that you're not ganging up on him if he had equal time.
Just an idea. Maybe some others will have a different perspective and opinions.
