Actually, it isn't an affair! And affair implies falling in love and all the associated crap that that can breathe. Ask any man who has had one, it is just trading in a old car for a new model, just to find out, it too will develop the same problems down the road, and he will be wanting a new upgrade, or it will cost him loads in repairs and maintenance.
Cynical I know, but hey. It is a friendship based on having done things a bit backwards, meaning getting the sex out of the way first and then getting to realize there is a person there you like and can get on with. Hey come to think of it most relationships start this way as well, the difference here is you don't have to have a second date, or call the morning after! Kisses Violette