I can see why you don't leave, as you're clearly not in love with him any longer.
But......you won't be spending your retirement with this man, and you are on very insecure, shaky ground.
He is not devoted to you, and he isn't fully invested in your family or your future. He is lying to you on a daily basis, so he is capable of leaving you high and dry at a moments notice. You have no idea what plans are in his head.
This will blow up in your face eventually. I have known a women who have been "other women". Without exception, feelings were involved from the female side, and the expectation was there, that the man would leave his wife, with the OW becoming increasingly pushy the longer that time went on.
How much longer before she turns up on your doorstep, because she feels like she's waited long enough?
You are living on quick sand, with him having all the knowledge (of his ultimate intentions) and thus all of the power.
You don't say how old you are? It's easier to meet someone else, the younger you are (if that's what you want?)
My ultimate advice would be to make sure that your own finances are rock solid and designed for a future away from him, for the inevitable day when he bails on you.
I actually left my ExH for cheating. We'd been together for 20 years, and had 2 young children. It took me 4 years to leave, and I can see now, looking back, how absolutely damaging that time was for me.
You think you're okay with all of this, but I suspect it is probably damaging you more than you realise, as you're still in the thick of it.