I used to resent the time my OH was out running as I saw it as a waste of time that we could be spending together - he sees his daughter on Sunday's so always did his long run on a Saturday which I considered to be 'my day'. Anyway, I began running myself and now I'm not bothered - I do my long run on whichever day suits me and he's fine with it - I also now appreciate the time it takes to cover the mileage (I'm a slow runner!!) and the time I get to myself doing something for me when I can just think about any old thing that comes into my head.
When he's in 'proper' training and out doing uber distances, I just make the most of the time by seeing friends, baking, taking the dog out, doing my own long run or just chilling at home. Ultimately he's going to do it anyway, regardless of whether I like it or not, so rather than fight about it I just accepted it and turned it to my advantage.
Fortunately for me, we don't have kids, so that makes it a bit easier for us. But even if we did I would never tell him he couldn't go out running - I would just expect a little common sense to be applied in that he fit it around family life.