It sounds like it does make much more sense for Charlie to stay at Chris parents while you are away and hopefully your mum will see that. Whatever happens, you both know youve made the right decision and try not to let it ruin the run up to the wedding - even if your mum does take it bad to start with, hopefully by the time you go away, she will see that its the best idea and shell be fine with it. Hope you get it sorted though x