M & FIL came down this w/end to see DD as DH has recently admitted 2 affairs and we are splitting up. PIL acted as if everything was 'normal' not sure they can actually admit their DS has done wrong. MIL has now retired and says she wants me and DD to go to France in the summer with her 'anytime as she has retired'. I do not want to go with her, she drinks a lot of red wine and lives in her own little bubble and smokes around DD which I HATE. We have been out to their french house for the past 3 years and i'd really like some time away from all of them. How do I let her down gently?