I love it! Thank you for those of you hat recommended it.
It's made me and DP take a look at our relationships with DS and I think without realising I was almost standing in the way of them having a good relationship.
Also looking back we realised that both DP&His brother were bought up this way and this is why though they adore their mum, there isn't the same respect for their Dad which isn't something we want to happen.
The more physical facts, like how/why a boy is less able to 'hold it' when he needs a wee, therefore resulting in more accidents if he waits to finish what he is doing, or the huge 100% increase in testosterone (explaining to DP that when he is desperate for a shag DS is feeling just as strong feelings just on other issues worked a treat).