If I remember it correct late 2016 someone on RD talked about a rumour of GA being in the plane with his mistress. But I can't find it anymore currently. But when I do I will link it overhere

Yes, that is where I read it. It was Grace Moore that was on the plane with him and I believe I read that they had spent extended periods of time together.
I was just surprised when I read here that his wife was devastated by his death and that he might have provided CG with a proper role model. I thought after reading that that maybe I had misunderstood something, but maybe not. If I had been his wife I don't believe I would be devastated by a cheating husband dying, but that is purely a personal response.
Does anyone know if it was GA or his father who was said to have had this passionate affair with Josephine Baker?
One sided unfaithfulness put into system is one if the most sadistic things anyone can do to anyone.
You don't just scream from the roof tops that your partner is inadequate and of no consequence, you do it to your kids too.
If the partnership was a matter of the heart to begin with at least, you attack someone where they're the most vulnerable, stick a thousand knives in their heart and turn them round to do the most harm possible. Vile.