Hey thanks for posting what must be a challenging situation for you both.
You know yourself the best option is to move on, as you said yourself. You'll find that you simply won't be able to do this since you still have a very strong bond with your ex – the classic Catch-22 situation, isn't it?
Sharing a bed, cuddles and massaging are all emotionally intimate experiences too. That just further in cementing the bond with him. And I'd expect this would also be driving a wedge into his current relationship – loving and sharing intimate situations with another person will definitely affect his behaviour at home with his current lady.
Could I suggest you focus on what you need to do to move completely away from any and all intimate relations with him? Only then will he be able to honestly face his current relationship in a clear light and make decisions on what he needs to do, without the confusion of you being in that particular equation?
It will allow you to also be clear on your own relationship future. Please do let me know if that makes sense as well as come back with any other factors we've yet to talk about.