Lusana
Don't worry about it!! The time to worry is when you've been on program for a few months and don't plan!!! Slip ups are bound to happen when you start and events take place. There's some good strategies in the overview thread here.

At a barbeque, I do a CM first and then when the desserts come out I do a huge RM!! People think I'm a pig but I'm happy. And on plan!! It does take some planning!!! I think more and more people are doing away with veggies at bbqs. You should always bring a veggie dish.