I usually said something like "S and I are going for a hike. You are welcome to join us if you want." We have always watched the Britcoms on public TV on Saturday nights - I would just let her know they were going to be on (this is after some DB'ing and stepping back a bit) - she would reply "Oh, great." Then when it was time, I just turned them on, sat down and watched. Without saying it, I left it up to her to decide whether she wanted to join me or not. No pressure from me.
As long as you are using a sincere tone (again, nothing over the top), it should not come off as being an a$$. I think it was Puppy who gave me a good way of regulating my beavior around W - act lik God himself were standing there watching me. Right now, it's important to approach her as a friend until she indicates she wants something more.
