I think what you are saying is... you want to stay friends with him and see if there is a chance, in the future, if they ever break up. My ex waited for me.. he was secretly in love with me and I met and moved in with another man... but he became my best friend and when me and that guy broke up 2 1/2 years later.. he was the first person I wanted to tell and then we got together.. and the rest, as we say is history.
But you know what? He didnt just wear a hair shirt and a chastity belt whilst he 'waited'.. he waited in his heart, but in reality, he also met and moved in with a gf and they were together for over 2 years.. It didnt matter to me.. if somethings meant to be, it will be. And it was never true love with our ex's.
I guess I am saying, you have to be realistic.. he is living with ow and making a life with her for now.. if he is ever going to come back to you.. he will anyway, even if you do go off travelling or date someone else.. and if you fell in love with someone else? Well, then it wont matter anyway will it.. your ship will have sailed. Capcihe? as T would say.
