Thankyou all for your comments and advice - they are really appreciated.
My wife popped round yesterday to get the boys - she spent 5 minutes making small talk as i was shaving in the bathroom and then continued while i got changed in the bedroom.
We then spent the day together at the museum with the kids and had a great time.
I went out yesterday night and my wife called me first thing in the morning to ask some mundane request and then wanted to know how the night went and was i away all night.
She seems to be persuing me for a change. Seems as soon as i stopped persuing her the roles reversed.
Although my wife loves me she says the spark has gone. If the things which caused the spark to die change / go away can the spark come back ????