An interesting book about a kind of continuous OBE relationship with the one person is described in the book,
Spiritwalker by Hank Wesselman.
It's based on naturally occuring OBEs during sleep and the time dilation is fascinating... i.e. 1 hour of sleep time = 36 hours in the other person's body. I think this book would be of particular interest to you Chronic as he describes being in the other person's body, having all his memories, feeling his sensations etc, and the contact is two-way.
The descriptions of the beginning of his experiences are strikingly similar to those of drug induced experiences such as black wiggly lines, coloured phosphenes and intense body load.
I'm still reading it, but over half way through it, it's proving to be very good.
The trees spoke to me through the wind. The more I listened, the more they spoke.