Do not let him build castles in the air if there is no attraction for you. If he is a friend, he knows you, so he will be able to know what you mean. But be honest, and keep that friendship.
Your home should be a pleasing place for both your nuclear families, but nothing major should be approved without the two of you being in agreement.
The cycle needs to end for the growth of both of you, not even about the children. Help him get that drive from himself because if he doesn't, he won't see the need to change.